That’s a long way from the all-time high of $702.10 they hit last September. If Apple’s stock continues along this downward trajectory, the company may soon cede its title of world’s largest company by market cap to Exxon Mobil, which it surpassed about a year ago. Apple’s current market capitalization is about $456 billion. Exxon’s is near $407 billion, and its shares have lately been on the rise. Obviously, there’s still quite a gap between the two, but if reports of weaker-than-expected sales of the iPhone 5 continue to dog Apple, or they prove true when the company next reports earnings, who knows?

For what it’s worth, there continues to be disagreement over just what is happening around iPhone 5 component orders. While some research houses, like Nonomura, have cut their Apple estimates to reflect the allegedly weaker-than-expected sales of the iPhone 5 reported by the Nikkei and The Wall Street Journal, others have taken issue with those reports, arguing that the reduction in component orders has nothing to do with weak demand. Said Wedge analyst Brian Blair, “… To suggest that iPhone demand has been halved sequentially from December is simply erroneous.”

That may well be the case — keep in mind earlier this month both Verizon and AT&T reported strong iPhone sales. And we’ll find out one way or the other when Apple reports earnings. But it’s worth noting that there are other explanations for a cut in iPhone 5 component orders. For one thing, estimates of 65 million iPhone units for the quarter were fantastically high to begin with, and suggestions that they’ve been suddenly halved seem dubious. That said, that theory makes a bit more sense if Apple ordered 65 million iPhone displays at a time when manufacturing yields were low, and then reduced the order when yields improved.

Another possible explanation: The reduction in orders is the result of a coming switch in display technology. Sources close to Apple tell AllThingsD that the company has been evaluating IGZO displays for use in its iOS devices, though they declined to say what the results of that evaluation have been. Finally, Apple could simply be ramping down component orders in preparation for production of the next iPhone.

All reasonable explanations, I think. We’ll find out which, if any, is the most accurate, on Jan. 23.

Apple shares, which closed Friday afternoon at an all-time high of $663.22, spiked to $680.87 in early trading on Monday — a new record high. At that price, Apple’s market cap rests at about $638.3 billion — yet another record. And with the next iteration of the company’s iPhone and a new, smaller iPad expected to debut in the weeks ahead, there are very likely more records in the offing.

Apple shares rose 1.85 percent today to close at $648.11 and carrying the company’s market capitalization past $607 billion. An astonishing rally for a stock that has already gained about 57 percent this year. Driving it: The looming launch of the next-generation iPhone and rumors of an iPad mini hitting the market in time for the holidays.

Given this kind of performance, it seems increasingly plausible that Apple really is headed for a $1 trillion market cap. As I’ve noted here before, Apple will become the world’s first trillion-dollar company when its share price hits about $1,072.

On that day, AAPL was trading at $420.31. Now, six months later, it’s hovering around $602. That’s a jaw-dropping rally. At that price, Apple shares are up about 48 percent for the year. And bullish observers continue to predict they’ll hit $1,000 by the end of next year. Which would give Apple a market cap of $1 trillion.

That’s an awfully big valuation. Is it reasonable?

David Einhorn, founder and president of hedge fund Greenlight Capital, believes it is.

During an appearance on CNBC this morning, Einhorn was asked if he sees Apple becoming a trillion-dollar company. His answer: “I would expect.”

“Apple is the best big-growth company we have,” Einhorn said. “It is the dominating brand in the area that it is in, and it trades at a multiple below the average in the S&P 500. I think that’s extraordinary.”

Einhorn professed himself to be an Apple bull, and he doesn’t see that changing anytime soon.

“We’re two, three years into the Apple investment, and the way it seems headed, it’s likely we’ll be there for a good while longer,” he said. “I think the stock is very, very substantially undervalued.”

On Tuesday, the company’s stock price closed at $11.09 — a price it has not seen since December of 2003. Another ugly decline for RIM, which has shed more than three-quarters of its value in the past year alone.

Evidently, the brief run-up in RIM’s stock price prior to the unveiling of the company’s long-awaited BlackBerry 10 operating system at BlackBerry World earlier this month has proved untenable. And the prospect of watching the first BB10 phones go head to head with the next iteration of Apple’s iPhone this fall has sent investors fleeing into the woods.

RIMM data by YCharts

As I write this, RIM’s market cap is hovering at just about $6 billion. Hard to believe that just five years ago that number was about $80 billion, and RIM was the most valuable company in Canada by stock market value.

White, who made headlines back in April by setting a $1,001 target on Apple shares, has raised that price to an even headier high: $1,111. Which is an interesting target, and not just for its numerical symmetry. As I’ve noted here before, Apple will become the world’s first trillion-dollar company when its share price hits about $1,072. So, by setting his target at $1,111 per share, White is predicting that Apple’s market cap will hit a trillion dollars sometime in 2013.

“Apple’s performance once again demonstrated how quickly Apple fever is spreading around the world, and this trend continues to drive meaningful upside in the company’s financial results,” White says. “We believe the negative vibes that have held back the stock over the past couple of weeks will now be replaced with the fear of missing the next leg up in the stock price that we are forecasting will reach $1,111 over the next year.”

$1,111.

That’s an awfully big valuation. But is it reasonable?

White contends that it is. And Apple certainly appears to be firing on all cylinders. Its gross and operating margins both set all-time records in Q2. It has sold more than 365 million iOS devices to date — 50 million in its most recent quarter. And it has already signed up more than 125 million subscribers to iCloud. Apple is a juggernaut, and there are still plenty of growth opportunities ahead of it.

Said White, “Apple is trading at just 8.1x (ex-cash) our CY13 EPS estimate, combined with our expectations for accelerated momentum over the next year with the iPhone 5, an Apple TV, an ‘iPad Mini’ and a potential relationship with China Mobile, gives us confidence that the stock has meaningful upside potential from current levels.”

With the broader market in decline, shares in the company rose to a new 52-week high this morning: $644. And that jump was enough to carry Apple’s market cap across the $600 billion threshold. This just about a month after the company reached the $500 billion mark.

Apple is the second company ever with a market cap to reach such stratospheric levels. The first: Microsoft, which nabbed a $604 billion market capitalization in December of 1999.

Apple’s market capitalization is now the largest in the world by far, dwarfing even that of oil juggernaut Exxon Mobil, which held that title for ages. And, as I’ve written before, a $1 trillion market cap seems less outrageous every day.

Impossible to say, though the company that’s likely at the top of the short list is Google.

With $44.63 billion in cash and cash equivalents on its balance sheet as of Dec. 31, the search behemoth is the most cash-rich tech company among the big dividend holdouts. In fact, it’s now the only tech company with a market cap above $100 billion that doesn’t offer a dividend.

And while Google hasn’t even hinted at offering a dividend anytime soon, some analysts believe the company is the most likely among its peers to consider one.

“We found that Google has the greatest capacity to return cash,” said Barclays analyst Anthony DiClemente.

Why?

“It probably has the most to gain in terms of positive sentiment by doing so, given its propensity for acquisitions and mixed investor sentiment around the Motorola Mobility deal.”

That’s certainly true. But there’s a problem with that view: Google is about to spend $12.5 billion of its cash stash on that Motorola Mobility deal. Now, Motorola Mobility had about $3.5 billion in its own coffers as of December 2011, with an estimated $3.2 billion of it on shore, but it’s unclear whether Google will combine the balance sheets of the two companies. Remember, the deal has yet to be consummated.

And then there’s that $4 billion in debt Google is carrying.

And a host of potentially expensive patent-related actions orbiting Android.

Add to that the fact that a big chunk of Google’s cash is held in overseas accounts and can’t be brought home without a massive tax hit and the company seems a far less likely dividend candidate that it does at first glance.

“With the completion of the Motorola Mobility deal, Google would have only around $3.5 billion in net U.S. cash/investments,” said S&P Capital IQ analyst Scott Kessler. “We think CEO Larry Page has reasons to practically and philosophically favor other uses of capital, and do not see a dividend anytime soon.”

Driven upward by excitement for the new iPad, which launches tomorrow and has garnered a slew of rave reviews, Apple’s stock hit $600.01 in early morning trading before slipping back down. This comes just about a month after it broke past the $500 level for the first time.

A stunning rally. Apple’s stock is up about 47 percent for the year, and seems destined to continue its ascent. Analysts certainly seem to think so: Earlier this week, Morgan Stanley and Canaccord Genuity both lifted their price targets on AAPL to above $700.

At $600, Apple has about a $550 billion market cap. At $700, its market cap would be around $603 billion.

And at somewhere around $1,072? $1 trillion.

Which is certainly a long way off, but not implausible. But another 18 months of printing cash at the rate it has been, continued growth in China, Brazil and India, and a few more big product launches — the iPhone 5 and that rumored HDTV — will bring it closer.

Said Canaccord analyst T. Michael Walkley, “We believe Apple is well positioned for very strong C2012/13 sales and earnings growth driven by new product introductions, including the iPad announced last week, the pending refresh of MacBook Air, an LTE iPhone likely in Q3/C2012, and potentially Apple TV in H2/C2012.”

And in 2012 — which also happens to be the 10th anniversary of the confab of tech and media titans — it’s already shaping up to be another fantastic event in terms of programming, with a lineup of onstage appearances that is sure to make some news.

There are many more very big names to come, but Walt Mossberg and I are pleased to introduce the first group of interviewees, which will give you a glimpse into the firepower we expect at D10 in late May. It is again being held in Rancho Palos Verdes, just south of Los Angeles.

The initial speakers we have confirmed so far include: New York City Mayor Michael Bloomberg; serial entrepreneur Sean Parker, who will appear with Spotify co-founder and CEO Daniel Ek; Zynga founder and CEO Mark Pincus; Federal Trade Commission Chairman Jon Leibowitz; LinkedIn Chairman and VC Reid Hoffman, who will appear with LinkedIn CEO Jeff Weiner; and Skype CEO Tony Bates.

It’s hard to imagine someone we have wanted to have onstage more than Michael Bloomberg, a man of many talents and interests. He’s known worldwide as the 108th Mayor of the City of New York. First elected in November 2001 (and again in 2005 and 2009), he is also one of the most compelling politicians in the U.S. today.

But Bloomberg is also a pioneer in terms of the business of digital news and information technology, having built a huge and groundbreaking media company and information service. Bloomberg (the company) has 310,000 subscribers to its financial news and information service, and more than 15,000 employees worldwide.

There will be a lot to talk about with him, from the upcoming presidential election to the state of our government to the future of innovation, news and technology.

Also sure to be voluble is Sean Parker, the legendary Silicon Valley entrepreneur who has been on the cutting edge of innumerable important digital trends of the recent decade. In 1999, Parker co-founded Napster, the controversial and industry-changing music service, at the age of 19.

He followed up with early contact information service Plaxo, and then shifted over to his critical involvement as founding president of Facebook in its early days as a start-up, an experience which was dramatized in the movie “The Social Network.” Parker continued to found and also invest in companies, from Causes to Spotify to his most recent, Airtime, a social video company that he is doing with his Napster co-founder Shawn Fanning.

Parker will be appearing onstage with Daniel Ek, another serial entrepreneur and technologist, who started his first company in 1997 at the age of 14. The Swedish native later co-founded online music phenom Spotify in 2006, with Martin Lorentzon.

The former CTO of Stardoll and founder of Advertigo leads a company that is changing the way music is delivered and consumed by fans, against a backdrop of intense change in the industry, succeeding even as a plethora of other services have stumbled.

Also a groundbreaker is Zynga CEO and founder Mark Pincus, yet another serial entrepreneur, whose latest effort in the online gaming arena has finally resulted in his biggest success. It recently went public, and now has a nearly $10 billion market cap.

Before founding Zynga in 2007, Pincus had already started three other companies: Push start-up Freeloader in 1995; automated tech-support company Support.com after that; and early social networking site Tribe.net in 2003.

(I met Pincus when he was at Freeloader in Washington, D.C., while writing a profile of him for the Washington Post, so I have enjoyed tracking his progress since then.)

Pincus is also an avid angel investor, with early stakes in Napster, Brightmail, Twitter and Facebook.

Reid Hoffman was another early investor in Facebook, along with many of Web 2.0’s most successful ventures. Well-known in Silicon Valley as an entrepreneur and VC, and recently dubbed the “start-up whisperer” by the New York Times (although I am not sure exactly what that means), he’s also chairman of LinkedIn, the business-networking service that also recently went public (at a $10 billion valuation, too).

He’ll appear with LinkedIn CEO Jeff Weiner, who started out life in Hollywood, but soon made his way to Silicon Valley as a top exec at Yahoo. After running its media division, Weiner spent a short time at venture firms before going operational again at LinkedIn.

What it takes to build and maintain momentum as tech companies move into more mature stages, as well as how the social networking space evolves, are among the many topics on tap for the pair.

The evolution of a start-up phenom — in this case, Internet telephony service Skype — will be among the topics covered by Tony Bates, who is now a president at Microsoft, which bought it last year.

As such, he is responsible, says the software giant in its description of his job, “for overseeing the company’s direction, strategy and overall mission to become a global communications service that will eventually reach billions of users.”

That’s a tall order for Bates, who came to Skype from a top job at Cisco. Bates has deep roots (or maybe, routing?) in the guts of the Internet, having done backbone-engineering strategy for Internet MCI. The U.K. native also holds nine patents.

Lastly, given all the activity we expect will happen between government regulatory agencies and tech companies over the next few years, we felt it was key to bring in FTC Chairman Jon Leibowitz. He has been at the FTC as a commissioner since 2004, but was given the top job by President Barack Obama in 2009.

Among his priorities, according to his bio, is “promoting competition and innovation in the technology sector through law enforcement and policy initiatives; and protecting consumers’ privacy — especially while they are using the Internet.”

Uh-oh!

Leibowitz knows from regulation, having served as the Democratic chief counsel and staff director for the U.S. Senate Antitrust Subcommittee from 1997 to 2000, where he focused on competition policy and telecommunications matters, as well as a similar stint at the Senate Subcommittee on Terrorism and Technology before that.

There will be a lot more speakers to come, of course. But, so far, we think D10 is off and running fast.

But Apple is fast closing in on it.

With its share price charting a new all-time high Thursday, the company’s market cap passed the $400 billion mark for the first time ever before slipping back in afternoon trading. It’s still within spitting distance of that milestone, though.

That said, it’s got a fair bit of ground to cover before it matches Exxon or surpasses it. The oil giant currently has a market cap of about $417 billion.

Steve Jobs at D8 | Photo by Asa Mathat

Jobs, who will become chairman, is handing over the day-to-day operations to former COO Tim Cook, who has deftly operated the company in Jobs’s absence before.

Still, investors are clearly uneasy with the top-level change, even though it has been a possibility for some time.

At one point, shares traded down $20.19, or 5.37 percent, to $355.99. That translates roughly to $18.5 billion in market value.

Investors, who recently pushed Apple shares high enough for the phone and computer-maker to overtake Exxon Mobil as the world’s most valuable company, obviously places overwhelming value on Jobs.

The stock had recently been trading higher on the expectation that the iPhone 5 would launch in October.

This is not the first time that Jobs’s sudden departure has shaken investors’ nerves.

Back in January 2009, shares dropped as much as 10 percent, or roughly $6 billion in market value, when the news broke that the CEO was taking a medical leave of absence.

At the time, AllThingsD’s John Paczkowski called investors wusses. “Yes, Jobs’s sensibility pervades Apple’s culture and its products, but that culture and those products are not tethered to his health or day-to-day presence at the company. And Apple’s deep executive bench is more than capable of running it — and running it well — in his absence. … Apple will endure — with or without Steve Jobs.”

Related posts

• Steve Jobs Resigns as CEO of Apple; Cook Takes Reins
• Steve Jobs’s Resignation Letter: “I Have Made Some of the Best Friends of My Life at Apple.”
• Apple Stock Falls After Jobs Announcement
• Steve Jobs Live on Stage in 2010 (Video)
• Tim Cook as Apple CEO: A Tested and Steady Hand
• Essay: Jobs’s Departure as CEO of Apple Is the End of an Extraordinary Era
• What Happens Next at Apple?
• Mossberg on Jobs (Video)
• Analysts Confident in Apple’s Prospects
• Apple Shares Bounce Back
• Tim Cook: Apple Will Continue to Make the Best Products in the World
• Does Tim Cook Need His Own Tim Cook?

An astonishing achievement for a company whose market cap bottomed out at $630.9 million back in 1982.

Incidentally, at $341.5 billion, Apple’s market cap is more than twelve times that of Dell’s $26.54 billion, which is highly ironic considering Michael Dell’s infamous suggestion for the company: “What would I do [with Apple]? I’d shut it down and give the money back to the shareholders.”

The company’s latest monster quarter and the surge in share price it inspired has set Apple on a path to overtake Exxon Mobil as the most valuable company in the world by market capitalization. Indeed, with a $358.9 billion market value on Thursday, Apple was just $62 billion short of Exxon’s $421.5 billion. And with a number of potential catalysts in the offing — the debut of a next-generation iPhone and the impending launch of iCloud, for example — some analysts say Apple may surpass Exxon Mobil within the next year.

“Apple continues to defy modern principles of economics and delivered the investment community something never seen before (e.g., quarterly revenue of $28.6 billion growing 80 percent year over year),” says Gleacher & Co. analyst Brian Marshall. “We expect Apple will become the largest market cap company on the planet when the stock hits approximately $445.”

There is a caveat to that prediction, though. Exxon shares must stay relatively flat. Which doesn’t seem all that likely. They’ve risen about 14 percent so far this year, and there’s no reason to think that growth won’t continue in the future.

That said, Apple has added more than $60 billion to its market cap in the last month alone. So, really, anything is possible — particularly if the company continues to turn in blowout quarters.

“I will make more profits and certainly there is no technology company in the planet which is as profitable as we are.”

— Microsoft CEO Steve Ballmer, May 27, 2010

What was unimaginable just a decade ago has finally occured. Apple is now more profitable than Microsoft.

Posting earnings for its most recent quarter Thursday, Microsoft reported net income of $5.23 billion on revenues of $16.42 billion. Which turned out to be significantly less than the net profit of $5.99 billion on revenues of $24.67 billion Apple turned in last week.

Another remarkable–and remarkably ironic–milestone for Apple, which surpassed Microsoft in market cap last May. It was Microsoft, after all, that breathed new life into a struggling Apple back in 1997 with a $150 million investment in the company (see video below). What was it Bill Gates said at the time? “We think Apple makes a huge contribution in the computer industry. And we think it’s going to be a lot of fun helping out.”

If wishes were horses, as the old proverb goes, all beggars would ride.

Or, in the case of the incessant corporate drama around Yahoo: If wishes were deals, all bankers would get big fat fees.

Even BoomTown has been harboring a big wish that there were some new scenario–instead of the same retreads that have been bandied about for more than a month–that was at least possible.

But because making up scenarios about the fate of Yahoo is all fun and games, it goes on and on and on.

Today’s latest intrigue is from Reuters, which reports that the Alibaba Group’s Jack Ma is considering entreaties by moneybags private equity folks to give him the many billions of dollars needed to buy back Yahoo’s 40 percent stake in the Chinese Internet giant and perhaps even participate in a takeover of Yahoo itself.

As has been reported here and in many places many times already, private equity and other investor interest has centered for a while on working with Ma to unlock critical financial value for anyone interested in doing any kind of buyout of Yahoo.

And, as it turns out, Ma has long been explicit about wanting to rid himself of Yahoo and to take back control of Alibaba completely.

There’s no doubt the government of China would also look kindly on that result too, many sources say, given the huge size of the vexing foreign ownership of one of the country’s brightest Internet stars.

But, as most also know, wishing–and even offering a giant pile of money–doesn’t make it so, unless Ma can convince Yahoo to sell to him.

And, of course, he also does not have to do anything either, since Yahoo management has little say over his actions at Alibaba, in spite of the large stake Yahoo holds.

As you can see, you can spin these ideas all day long, which is what bankers apparently get paid so much for.

Luckily, I will do it for free.

You could, for example, add Microsoft into the Yahoo mix once again. Would it engage, in order to get the search business in China from Alibaba? Or to finally unload its pricey MSN unit?

And what of News Corp., with its extensive ties in Asia and interest in trading its weak digital properties, such as Myspace, for something better? Wasn’t CEO Rupert Murdoch sniffing around before?

There is also a renewed scenario for Demand Media to become involved.

Of course, let’s not leave out the old faithful plots about how tiny AOL, with its high-Q-quotient CEO Tim Armstrong, could still be a contender.

Just for fun, I will add another interesting idea I recently heard: Comcast. Could the cable and now media giant swoop in at some point and pick up a lot of digital assets it might need going forward?

Don’t forget Disney either–the Hollywood entertainment giant, which has a key interest in moving into the digital space even more boldly.

On consolation: Google is probably out, having been burned before, because of all the antitrust issue inherent in any hookup with Yahoo.

Of course, it will not be a party until Twitter gets here, with its date Zynga.

Finally: Where, oh, where is the holy union of Facebook CEO Mark Zuckerberg and Apple CEO Steve Jobs when you need them to knock this corporate drama into the stratosphere?

Until it is all sorted out for real, here is a reprint of some of the many similar scenarios I cooked up way back in late September–most of which were investor fantasies, but now are being taken more seriously–in a post titled “Could AOL Merge With Yahoo? Could News Corp. Make a Play? Takeover 2.0 With a Little Help From China’s Alibaba?”

Enjoy–although, as you will see, it’s the same scenarios floated then as now:

Today, as news of the departure of Yahoo’s U.S. head Hilary Schneider and two other top execs got around Wall Street, investors and dealmakers were actually thinking of things other than executive turmoil.

As in: Does the uncertainty, along with a naggingly lackluster stock price and weak growth, create pressure on its CEO Carol Bartz and its board to do something dramatic?

In addition, does the messy public situation even provide an opportunity to put Yahoo into play, despite its market cap of $19 billion?

These and many more are the scenarios being debated in boardrooms of big media and Internet companies today, as well as at private equity firms, investment banks and even in Asia.

That’s because many are focusing on Yahoo’s Asian investments. Yahoo itself owns almost 35 percent of Yahoo Japan and a 40 percent stake in China’s Alibaba Group, assets that now make up–along with cash on hand–most of the company’s valuation.

Alibaba and Yahoo have recently gotten into an ugly public tussle over the Chinese firm’s desire to buy back the shares now, with Bartz holding out for more appreciation.

Now, she might have to do a deal with Alibaba, according to one theory, because a sale of its stake would give Yahoo’s stock a significant boost.

One problem: Alibaba CEO Jack Ma has made it known to anyone who will listen that he loathes Bartz personally, after a series of awkward encounters. That said, he has a close relationship with former Yahoo CEO and co-founder Jerry Yang, who is on both companies’ boards.

That puts Ma in an interesting position, according to another theory, because other U.S. companies with an interest in Yahoo might try to make a deal with him to do some kind of deal with Yahoo.

Most frequently mentioned by big investors in Yahoo: AOL and its CEO Tim Armstrong.

Armstrong, said sources, has not shied away from the idea of Yahoo acquiring AOL and installing him as CEO with Bartz as chairman. AOL’s valuation is just $2.65 billion.

Although AOL has also been trying to turn itself around and is in a much less powerful position than Yahoo, Wall Street likes Armstrong’s story for AOL as a modern-day media and media distribution company.

“At least he has a narrative that is believable,” said one big investor in both companies. “Bartz has no vision.”

Another plus for Armstrong: His friendly and Don Draper-smooth demeanor, in contrast to Bartz’s tough-talking and now too-often curse-laden patter.

And while, Armstrong has assembled an experienced staff. And he himself has deep online advertising sales experience, given his last job as head of U.S. sales at Google.

Also likely to be interested: News Corp. The reason is that its own digital efforts, especially at the MySpace social networking site, have gone sideways.

And there’s history: News Corp. tried to facilitate a merger of MySpace, MSN and Yahoo into a company codenamed “TrafficCo” at the time Microsoft was attempting a takeover of Yahoo.

It was supposed to be headed by former Microsoft exec and now Juniper Networks CEO Kevin Johnson, another possible Yahoo CEO candidate.

That plot did not pan out and News Corp. has been trying mightily to revive MySpace ever since. It certainly would trade it into Yahoo for some stake.

Another hook: Its digital head Jon Miller, who used to be CEO of AOL, almost was CEO of Yahoo, during that same takeover fight. But a noncompete agreement with Time Warner was enforced by CEO Jeff Bewkes at the time.

Both AOL and News Corp. could certainly make approaches to Ma or Yahoo Japan’s Masayoshi Son to agree to help them get back their Yahoo stakes.

Son was the one who made the move recently to switch out Yahoo search for Google in Japan.

And, by the way, Son was one of Yahoo’s earliest investors.

Confused? Well, it is certainly shaping up to be a lively Silicon Valley goat rodeo, as there are also all kinds of private equity companies with spreadsheets already figured if Yahoo shares decline enough.

And there are other ideas spinning on spins into Yahoo, such as Demand Media, which is prepping an IPO, and its perpetually enthusiastic CEO Richard Rosenblatt.

One unlikely player is Microsoft. The once hostile suitor is now a partner to Yahoo in search and online advertising.

Of course, the last and biggest question is what happens between Bartz and the board. While they seem to have backed her this far, she has not performed as she has promised and now seems to have gotten publicly grumpy about all the pressure to do so.

Will the directors, who proved themselves pretty ineffectual in the past, continue to support her? Or will they find some self-protecting way to ease her out?

Some directors are definitely unhappy, sources said, but no one seems to be in charge or particularly influential.

Which could mean even more confusion as Yahoo moves unsteadily forward.

Apple’s shares broke $300 for the first time last week, pushing its market cap to well past $280 billion–second only to that of oil behemoth Exxon Mobil. Should the company’s rally continue, it won’t be long before it overtakes Exxon on the Standard and Poor’s 500.

And there’s no reason at all to think that it won’t. Apple is scheduled to report its fourth quarter results today after the bell, and by most accounts it will be another blowout. Consensus among analysts seems to be that strong sales of the iPhone 4, the iPad and the Mac will push Apple’s earnings per share to $4.05 on revenue of $18.8 billion–quite a leap over the earnings of $1.82 per share on revenue of $9.87 billion the company posted during the same period last year.

And according to some analysts, this quarter’s leap may well leave the company poised for an even higher one in the next quarter. Said UBS analyst Maynard Um, “With continued momentum in all product lines as well as easing supply constraints for both iPhone and iPad, we see the potential for Apple to surprise to the upside on guidance again.”

Apple (AAPL) stock is clearly on a tear and will be for some time. But that doesn’t mean it is risk-free, says Bernstein Research analyst Toni Sacconaghi. In a research note issued this morning, he outlined his bear case for the stock, pointing to five potential pitfalls that might undermine it.

“These five concerns are as follows,” writes Sacconaghi. “(1) Apple’s market cap is too large for it to outperform, and its image has migrated from underdog to Silicon Valley bully, which will increasingly pit competitors against it; (2) Increased regulatory scrutiny threatens to undermine Apple’s powerful iOS ecosystem; (3) Sustained growth in iPhones will inevitably lead to margin pressure; (4) Near-term expectations for iPhone and iPad units are getting heady, risking disappointment; and (5) Apple insistence on retaining cash points to a risk of the company squandering it on a flawed acquisition.”

Sacconaghi makes a case for each, but in most instances, it’s a bit of a stretch and seems to hinge on hypothetical scenarios (what if content providers collectively choose to support a non-Apple platform) or unfavorable outcomes to developing scenarios (what if the Federal Trade Commission finds Apple’s behavior in the mobile advertising market to be anticompetitive). So much so, that in the end, the analyst concludes that none of them presents an imminent threat.

“We have articulated the bear case for Apple investors principally as a checklist of issues to monitor,” he writes. “At this point, none of the aforementioned potential pitfalls concerns us sufficiently to change our earnings estimates or price targets….We continue to view AAPL as the most secularly attractive name in our coverage universe.”

Guesstimating the total size of that business makes for good Web sport, and Reuters makes a run at it today: The news service pegs Facebook’s 2009 revenue at “$700 million to $800 million” and reports a “solid net profit, in the tens of millions of dollars,” citing two anonymous sources.

Those numbers are higher than other ones we’ve seen, but they don’t sound unbelievable. Facebook now boasts enormous size–half a billion users!–and at least three different revenue streams: Traditional display ads sold by a top-flight sales team, self-serve ads (check out this do-it-yourself tweak) and virtual goods (read: Zynga).

What Facebook doesn’t have, as best as I can tell: A magic moneymaking bullet a la Google’s (GOOG) AdWords. That may prevent the company from getting a Google-like market cap when and if it goes public. But I don’t think Mark Zuckerberg and company are complaining.

“We have to let go of the notion that for Apple to win, Microsoft needs to lose.”

— Apple CEO Steve Jobs, August 1997

And there it is. Today Apple, not Microsoft is the world’s most valuable technology company.

As I write this Apple (AAPL) shares are trading at $244.87, giving it a market capitalization of $223.1 billion. Meanwhile, shares of Microsoft (MSFT) are trading at $24.79 and the company’s market cap sits at $217.78 billion (see table below; click to enlarge).

And so Cupertino has finally surpassed Redmond in total value. The only American company with a market cap greater than Apple is Exxon Mobil (XOM).

UPDATE: Apple closed the day well ahead of Microsoft. Its market cap: $222.07 billion; Microsoft’s: $219.18 billion.

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• Dueling Market Caps: Apple and Microsoft