A range of major players interested in acquiring all or a large piece of Yahoo have been prepping possible bids and have been in touch with the Internet giant’s board over the last several days.

While Yahoo has publicly said it was not for sale, according to numerous sources both inside and outside the company, it has been receptive to the interest and its Chairman Roy Bostock and Co-founder Jerry Yang have spoken to several.

Among the possible players: Silicon Valley venture firm Andreessen Horowitz, which is working with private equity firm Silver Lake, in a deal that also might include Russia’s DST Global and Yahoo’s Japanese partner Masa Son; former News Corp. exec Peter Chernin, who is partnered with Providence Equity Partners; and the possibility that Yahoo’s Chinese partner, Alibaba Group, might consider entering the fray in what could be a reverse merger of sorts.

Also being rung up by some of the parties: Microsoft — Yahoo’s advertising and search partner — which is being seen as a possibly moneybags in any deal.

The movement among these investors is against a backdrop of increasing pressure for Yahoo’s board, after it fired CEO Carol Bartz last week. In the wake of the dramatic move, shareholders have upped criticism of Bostock and the board and have been looking hard for alternatives.

Today, that included hedge fund investor Daniel Loeb of Third Point, which has a 5.1 percent stake in Yahoo. In a filing this morning, he said he might increase that amount, and described a testy hour-long phone call he had earlier this week with Bostock that ended abruptly with a hang-up from Yahoo.

Sources said Loeb called Bostock a “fool,” among other not-so-nice names, on the call and asked for Yang’s help in dumping him.

This comes as exactly no surprise, given his previously strong letter in which Loeb called for Bostock’s ouster.

Loeb has been calling out Bostock — who is also on the boards of Morgan Stanley and Delta Airlines — for a series of gaffes at Yahoo since he became chairman in 2008 (he’s been on the board since 2003).

Those have included: Yahoo’s bungled effort to stave off a takeover by Microsoft several years ago; the too-long enthusiasm for Bartz, who was hired in early 2009 and fired last week; sitting unusually still as competitors such as Facebook, Google and more have out-innovated and outgrown Yahoo; and, of course, the falling knife of a stock, which has dropped precipitously since Bostock has been in charge of the board.

As Loeb wrote in a letter he sent to the company last week:

“It is time that certain members of this Board were held accountable for its past failures and their individual roles. Accordingly, we insist that Mr. Bostock, who championed Ms. Bartz’s hiring and led the charge against the Microsoft deal, promptly resign from the Board.”

Loeb is likely to add to that later today at a high-profile investor conference in New York, where the colorful but tough-talking investor is sure to add more logs to the fire.

But it not only him. Other major shareholders of Yahoo are also in touch with possible outside buyers, seeking a change at the long-troubled company, after its shares have remained in the doldrums, its attrition rate of employees has spiked and its product pipeline has slowed to drip.

This has all been taking place — of course — during one of tech biggest and most innovative booms, in which Yahoo competitors have grown strongly.

Enter Marc Andreessen, the well-known entrepreneur who has transformed himself into one of Silicon Valley’s most powerful venture capitalists.

He and his partner Ben Horowitz recently pulled off another similar deal — with Silver Lake — to take control of a then-troubled Skype. They later flipped it to Microsoft for a large return.

Sources familiar with the situation said the pair have become increasingly intrigued by the situation at Yahoo and believe that its assets and brand are still strong, despite its management turmoil in recent years.

One problem is the huge cost of almost any kind of takeover and also the complexity, given much of Yahoo’s $18.5 billion valuation is due to its Asian assets.

The sale of those shares, as well as the selling off of some of Yahoo’s less core properties, makes for a very complicated situation for anyone.

Said one person looking at the company: “It is one of the more massive hairballs around.”

That is a common sentiment among many of those looking at Yahoo, which has hired Allen & Co. to manage the process.

Also of worry is a bid that would include too many players. Yahoo has long been plagued by indecisiveness on the part of its execs and, mostly, its board.

But one thing all the possible buyers of Yahoo, as well as an increasing number of its shareholders, agree on: The Yahoo board needs a major shake-up.

As Loeb wrote last week, which many I interviewed also echoed:

“This letter details our principled demands for sweeping changes in both the Board of Directors (the “Board”) and Company leadership, and outlines the hidden value of Yahoo, which has been severely damaged — but not irreparably — by poor management and governance.”

Second, Amitabh Srivastava, head of Microsoft’s Azure cloud platform business, announced that he’s leaving the company. Srivastava, who joined Microsoft in 1997, was widely considered to be a possible successor to Muglia, but lost out to Nadella.

One of the few ever to be named a Distinguished Engineer at Microsoft–an honor now known as Technical Fellow–he was tapped, along with Brian Valentine, by then Windows chief Jim Allchin to take over the Windows engineering efforts in 2003 at a time when the operating system was being widely derided as plagued with security and other problems. Srivastava had his team draw up a map depicting how all the various pieces of the Windows source fit together. It was eight feet tall, 11 feet wide, and was described in a 2005 Wall Street Journal story as looking like a “haphazard train map with hundreds of tracks crisscrossing each other.”

Srivastava and Valentine are credited with the 2004 proposal to streamline how all those pieces functioned, a plan that would allow various features to be added or removed without disrupting the whole operating system. The idea was a partial response to the looming threat from Google, which that year had launched Gmail. The problem was their plan required throwing out a lot of legacy source code that had been in Windows for years, and starting fresh.

Srivastava’s changes included automating testing on features that had for years been done by hand. Code with too many bugs were sent to “code jail.” Over time, code flowing into what was to become Windows Vista improved.

We all know what happened with Vista–it too was widely panned. But the engineering processes put in place had a lot to do with the many improvements that appeared in Windows 7.

Srivastava then moved on to a new Microsoft project in 2006, code named Red Dog, now known as Azure, which launched in 2008. From this he pivoted to running the server and cloud division, overseeing Microsoft’s relationships with enterprise and data center customers.

People I’ve been talking to who tend to know a lot about the internal politics at Microsoft say this isn’t the last of the changes. Now that Muglia’s replacement has been announced, Nadella is going to want to name key members for his team, which means that those not tapped will probably choose to leave as well. The management shake-up at Microsoft is not over yet.

Srivastava has a Ph.D. in computer science from Penn State, and was invited to deliver the commencement address at the school’s College of Engineering in 2008, which is in the video below. Key quote: “In the end, it’s all about execution.”

Funny how that works. It was Dell himself, after all, who had a big hand in pushing the price as high as it went. 3Par, you’ll remember, was the subject of an epic three-week bidding battle between Dell and HP. When it was over, HP took home the prize, shelling out $2.4 billion for 3Par.

The deal kicked off a flurry of acquisitions in enterprise storage. IBM went on to pick up Netezza, and EMC bought Isilon Systems in November. Dell ultimately did make a deal in the storage space, dropping $960 million for Compellent in December.

At Davos, Dell proceeded to pat his eponymous company on the back for its “discipline” by not raising the bidding price for 3Par even higher. He also said he’s looking to do more acquisitions aimed at data centers and cloud computing.

It didn’t take long for HP to answer: Chairman Ray Lane, fresh off the shake-up that rocked the company’s board last week, told Bloomberg in a separate interview that Dell had been willing to pay “almost what we paid” for 3Par. He does have a point.

And with 9.2 million Google shares, it’s not like he needs the money, though his stake has suffered a significant decline in value since the company’s executive office shake-up. Prior to the announcement, Google shares were trading at around $641, making Schmidt’s stake worth about $5.9 billion. Today, they’re hovering around $608, making that stake worth $5.6 billion–down $300 million on news he’s stepping down as CEO. That’s a nasty little drop any way you look at it, though I’m sure the obscene size of the remaining sum makes it a bit easier to stomach. Perhaps the residuals from that new Eric Schmidt talk show reportedly in the offing will make up for it….

PREVIOUSLY:

• Talking Schmidt: Google’s CEO in His Own Words
• A Big Quarter From Google, and Shake-Up at the Top–Larry Page to Become CEO

The various boardroom dramas that have roiled HP’s directors during the last decade have often overshadowed HP itself. Last August’s blowup involving the departure of CEO Mark Hurd following accusations of sexual harassment occurred against the backdrop of lingering memories of the 2006 scandal involving the use of illegal methods to spy on journalists that ended the tenures of three HP directors.

Before that there was a public fight against HP’s 2002 acquisition of Compaq, led by dissident director Walter Hewlett, who eventually lost his seat. The Compaq deal ultimately cost Carly Fiorina her job at HP after a boardroom confrontation in 2005.

The result of all this is that boardroom drama has become something of an HP specialty, along with printers, computers and IT services. Criticizing the board’s actions has become something of a sport, with Oracle CEO Larry Ellison serving as the most public practitioner.

Shareholders appeared to agree that a change was overdue. HP shares shot up right away as word of a shake-up began to leak right before markets closed yesterday. HP shares closed up one percent today, trading at levels not seen since before Hurd’s abrupt departure in August.

The four departing directors were deeply involved in the Hurd kerfuffle. Two were Hurd defenders, and the other two wanted him out. All four volunteered. Chairman Ray Lane, in an interview with The Wall Street Journal, said the debate over Hurd’s status “took a lot out of this board.”

It’s highly unusual for a company to change its board so deeply and so suddenly. The five new additions became directors effective today without any input from shareholders, and will serve until a vote can be held to approve them for a full one-year term at the next shareholder meeting in March.

Shareholders in theory have the power to offer their own slate of directors, but there’s little time for that, and even if some group were to do so, its only option would be to do so at its own expense. SEC rules governing the access to the proxy nominating process are currently being challenged in court by the U.S. Chamber of Commerce and Business Roundtable, and so the rules that would allow shareholders to more easily submit their own list of names are on hold pending the outcome.

Absent a proxy challenge, HP shareholders will be put in the position of accepting a board on which seven of 13 directors are brand-new. That’s a lot of new blood and may turn out to be the kind of change HP’s board needs. And getting the change done all at once rather than gradually may prove the better option.

However, I can’t help but wonder: In seeking to close out a period in which HP’s board became known more for its drama than anything else, is more drama the right answer?

The Street was looking for $6.06 billion and $8.09 a share.

Also, importantly, a shake-up at the top. From the release:

* Starting from April 4, Larry Page, Google Co-Founder, will take charge of Google’s day-to-day operations as Chief Executive Officer.
* Sergey Brin, Google Co-Founder, will devote his energy to strategic projects, in particular working on new products.
* Eric Schmidt will assume the role of Executive Chairman, focusing externally on deals, partnerships, customers and broader business relationships, government outreach and technology thought leadership–all of which are increasingly important given Google’s global reach. Internally, he will continue to act as an advisor to Larry and Sergey.

Here’s the full text of Schmidt’s statement explaining the move:

When I joined Google in 2001 I never imagined—even in my wildest dreams—that we would get as far, as fast as we have today. Search has quite literally changed people’s lives—increasing the collective sum of the world’s knowledge and revolutionizing advertising in the process. And our emerging businesses—display, Android, YouTube and Chrome—are on fire. Of course, like any successful organization we’ve had our fair share of good luck, but the entire team—now over 24,000 Googlers globally—deserves most of the credit.

And as our results today show, the outlook is bright. But as Google has grown, managing the business has become more complicated. So Larry, Sergey and I have been talking for a long time how best to simplify our management structure and speed up decision making—and over the holidays we decided now was the right moment to make some changes to the way we are structured.

For the last 10 years, we have all been equally involved in making decisions. This triumvirate approach has real benefits in terms of shared wisdom, and we will continue to discuss the big decisions among the three of us. But we have also agreed to clarify our individual roles so there’s clear responsibility and accountability at the top of the company.

Larry will now lead product development and technology strategy, his greatest strengths, and starting from April 4 he will take charge of our day-to-day operations as Google’s Chief Executive Officer. In this new role I know he will merge Google’s technology and business vision brilliantly. I am enormously proud of my last decade as CEO, and I am certain that the next 10 years under Larry will be even better! Larry, in my clear opinion, is ready to lead.

Sergey has decided to devote his time and energy to strategic projects, in particular working on new products. His title will be Co-Founder. He’s an innovator and entrepreneur to the core, and this role suits him perfectly.

As Executive Chairman, I will focus wherever I can add the greatest value: externally, on the deals, partnerships, customers and broader business relationships, government outreach and technology thought leadership that are increasingly important given Google’s global reach; and internally as an advisor to Larry and Sergey.

We are confident that this focus will serve Google and our users well in the future. Larry, Sergey and I have worked exceptionally closely together for over a decade—and we anticipate working together for a long time to come. As friends, co-workers and computer scientists we have a lot in common, most important of all a profound belief in the potential for technology to make the world a better place. We love Google—our people, our products and most of all the opportunity we have to improve the lives of millions of people around the world.

His shorter comment, via Twitter:

Here, again, is a cheat sheet from Citi’s Mark Mahaney, so you can play along at home:

Here is her entire memo:

Getting our house in order

Posted February 26th, 2009 at 9:16 am by Carol Bartz, CEO

A month and a half in the saddle and today I have the perfect excuse to get blogging.

I’ve been on a whirlwind tour for the last six weeks, talking with everybody from executive leaders to the guys who configured my laptop. I’ve been in student mode, slowly getting smarter about what makes this place tick. And most recently, I’ve been gathering information on what it’s going to take to get Yahoo! to a great place as an organization–and one that brings you killer products.

People here have impressed the hell out of me. They’re smart, dedicated, passionate, driven, and really nice. There’s so much great energy and frankly lots of optimism. But there’s also plenty that has bogged this company down. For starters, you’d be amazed at how complicated some things are here.

So today I’m rolling out a new management structure that I believe will make Yahoo! a lot faster on its feet. For us working at Yahoo!, it means everything gets simpler. We’ll be able to make speedier decisions, the notorious silos are gone, and we have a renewed focus on the customer. For you using Yahoo! every day, it will better enable us to deliver products that make you say, “Wow.”

I’ve noticed that a lot of us on the inside don’t spend enough time looking to the outside. That’s why I’m creating a new Customer Advocacy group. After getting a lot of angry calls at my office from frustrated customers, I realized we could do a better job of listening to and supporting you. Our Customer Care team does an incredible job with the amazing number of people who come to them, but they need better resources. So we’re investing in that. After all, you deserve the very best.

We’re also leaning on this team to make sure we’re all hearing the voice of our customers (consumers and advertisers). I’m singularly focused on providing you with awesome products. Period. The kind that get you so excited, you have to tell someone about them. Whether on your desktop, your mobile device, or even your TV.

And that takes a real understanding of what you want/need/love/hate, how you’re using our products, and what you find simple, intuitive, easy and fun. Who wants innovation for innovation’s sake if it doesn’t make your life easier, more efficient, more productive? So expect us to hear you better and take better care of you.

Finally, a note about our brand. It’s one of our biggest assets. Mention Yahoo! practically anywhere in the world, and people yodel. But in the past few years, we haven’t been as clear in showing the world what the Yahoo! brand stands for. We’re going to change that. Look for this company’s brand to kick ass again.

Big thanks to the many of you who’ve reached out with positive comments. It’s clear people want Yahoo! to succeed. I’ll try to pop by here again soon, though probably not too soon. I have a pretty long to-do list.

Carol Bartz

CEO