Goldman offered the news in a conversation at LeWeb, saying he’d maintain an advisory role, that he’s not leaving to start something new, that he’s not going to Facebook or Google and that he just needs “a bit of a break.”

Twitter has no lack of product leaders, including co-founder and former CEO Evan Williams, who recently relinquished the top job to make room for former COO Dick Costolo. Goldman had been a close friend of Williams, having first joined him as business manager of blogging software maker Pyra Labs, before it was bought by Google in 2003. Goldman has led product at Twitter since 2007.

Following Goldman’s departure announcement, a company spokeswoman said that Williams “is going to continue in his co-founder role and help with product vision.” She said that it was not yet clear whether the new head of product management would be an internal or external hire.

But, no surprise, sources familiar with the situation said Williams will likely assume the top product role, as it’s the best-fitting landing place for him at the company. The Twitter service was originally created in 2006 by company co-founder and Chairman Jack Dorsey and others when Williams was CEO of a previous start-up called Odeo. Dorsey left his operating role at Twitter in 2008 when Williams replaced him as CEO.

As the company verges on raising funding that would value the company at $3.5 to $4 billion, the departure of Goldman seems to underscore an issue that has plagued Twitter for a long time: Product development.

Aside from its well-documented reliability problems, new products and major upgrades at Twitter are few and far between.

While it is clear the people who founded and now lead Twitter have been passionate and visionary about personal expression and information-sharing in its simplest form, many techies say they are given pause by Twitter’s deficit of innovation since its first and most powerful iteration.

They assert that Twitter’s product launches to date–retweets, lists, some apps and its #newtwitter Web interface–are minor complements to the simple messaging system. In a tech culture that values shiny new toys, multiple people have said to me that Twitter is the least innovative of any other Internet contemporary.

For example, Twitter still doesn’t offer image hosting or its own link shortener, and still has yet to fully incorporate the search service Summize, which it bought in 2008. Perhaps that’s out of concern for displacing and angering its developer corps of companies, like Bit.ly, but since 25 percent of Tweets contain links, it seems obvious that Twitter should help its users shorten them to help fit into its 140-character limit.

The company tried to set a firm road map last April at Chirp, its first developer conference (pictured at left, the dudes of Twitter held a jokey Q&A session at Chirp).

But since then, eagerly awaited products like “Annotations” (a way to add more information to Tweets) have been delayed as the company concentrated on dealing with World Cup traffic and the release of its new Web site. Twitter is hiring as fast as it can, with its ballooning employee count, now at 325, relatively small for a product now used by eight percent of American online adults.

Still, many laud the sleek new Twitter Web site–for which Goldman, Williams and product manager Kevin Cheng led development. It was rolled out to admirable acclaim and user satisfaction.

But Twitter has only a few weeks to shuffle things around before it launches into the new year with no formal leader of its product team.

The All Things Digital readership has spoken: Facebook CEO Mark Zuckerberg was wrong in declaring that the Apple iPad was not mobile.

In fact, 1,671 takers of a survey BoomTown ginned up on the subject using SurveyMonkey disagreed with him 85.1 percent to 14.9 percent.

The larger number picked the answer– “No, Mark needs to get out more!”–when asked: “Was Facebook CEO Mark Zuckerberg correct in asserting last week that the Apple iPad is not mobile?”

The smaller number agreed with the statement, “Yes, Mark is a visionary!”

Well, he actually is, but not about this debate.

A week ago, BoomTown wrote a post titled “Dear Zuck: The Apple iPad Is Mobile (So Sorry!),” countering Zuckerberg’s sudden statement at a recent press event that the popular tablet device was not.

As I wrote about what the kingpin of the social networking giant said:

Ben Parr of Mashable asked a question everyone has been speculating about recently–whether and when there would be an iPad app for Facebook coming.

A fumbling “no comment” would have worked fine, but the real Zuckerberg seemed to have decided to channel the clever Aaron Sorkin-ish repartee of the fictional Zuckerberg in the movie “The Social Network.”

“It’s not mobile…it is a computer,” he said flatly.

“I think Apple would disagree with you,” noted Parr.

“Well, sorry,” Zuckerberg spat out, his voice dripping with the kind of sarcasm that only a super-nerdy Silicon Valley engineer can pull off properly.

I disagreed, noting:

The iPad is a computer, because that is technically true, even though that makes a smartphone a computer too. (And, now that I think of it, my car is a computer.)

But actual civilians don’t make these kinds of distinctions and, if one spends any time watching consumers use tablets, mobile is entirely how they think of it.

The post got a lot of comments, and tweets on Twitter too, so I thought I would post a survey so that everyone could cast their own vote.

Here it is below again, with the results under it (click on full screen to make it ginormous):

SurveySummary_11092010

[Photo from CafePress, and thanks to SurveyMonkey for calling our survey a "smart, savvy, and even downright sexy" embed.]

In BoomTown’s bold quest to annoyingly stick a Flip digital video camera in the face of every Yahoo senior exec, this week I worked the last nerve of its CTO and EVP of Products, Aristotle “Ari” Balogh.

Actually, the 45-year-old Balogh is a very calm and pleasant man, especially considering the huge responsibility that has been foisted on him by CEO Carol Bartz to rejigger how Yahoo (YHOO) makes its products and services and deploy its technology in a more efficient, centralized and most of all, innovative manner.

It is actually a process that was started under the previous leadership, especially President Sue Decker.

But now, after a number of reorgs, a wide swath of Yahoo is under Balogh’s purview–from search to open initiatives to product development to trying to fix Yahoo’s big problem of never quite getting its innovations out the door.

To explain all this, Balogh sat down with me twice–he is clearly a glutton for punishment–to talk about where Yahoo stood as it sought to dig itself out of its long slump and reemerge as the potent Internet force it once was.

While he successfully avoided the questions about Yahoo’s talks to do a search and advertising partnership with Microsoft (MSFT), he did talk about his view of its new Bing search service (well done, but can it scale?–which is an engineer’s favorite schoolyard taunt).

He also addressed the bigger question of how Yahoo can stay relevant in the fast-changing Web 2.0 world.

To Balogh, copying trendsetters like Facebook is not the answer. For example, he noted that Yahoo is more a place where consumers do “one-way” follows of things important in their lives rather than wanting another social-network service (which Yahoo has tried and failed at, actually).

“We’re not going to be another social network,” said Balogh flatly, agreeing that that boat has already long sailed without Yahoo on it with a significant product–Yahoo famously failed to buy Facebook, well before Balogh arrived in early 2008 from VeriSign (VRSN). “But we can be a place where people make and manage the important connections they have.”

How this will all play out is one of the most interesting questions in Silicon Valley because–even after all the turmoil–Yahoo remains one of the largest sites on the Web.

About 500 million monthly unique visitors enter its homepage and course through its vast site constantly, from its search pages to its massive email and instant-messaging services and its popular suite of content sites.

No one says Yahoo is not big–what everyone says is that it has missed many major and critical Internet trends as it has become mired in a management morass and external battles.

Now, with new leadership in place, observers are waiting to see what’s next.

In this regard, it is important what Balogh thinks since he is perhaps Yahoo’s only person who even closely resembles a Web product visionary now that former CEO and co-founder Jerry Yang has stepped aside and Bartz has taken up command.

While he typically shies away from the spotlight, he is not bashful about talking about Yahoo’s infamous lugubrious development process.

“We have pockets of great technology that we have to really put back together into a coherent infrastructure,” said Balogh. “We have to get the basics right and focus on those core daily experiences that make Yahoo extraordinary.”

That is easier said than done, especially when changes impact so many consumers and, of course, the bottom line. Choosing what key trends to attack is harder for a large public company like Yahoo, which has a lot to protect in its current businesses.

“There will always be a battle between new ideas and monetization,” said Balogh. “The question is how much do you push that line back and forth?”

That fine line will surely be tested with the rollout of its new homepage in the fall, a long project that has been codenamed “Metro.”

“It is not a radical departure, but we have given users more power to do what they want and also serve as the best of Web versus that is already inside of Yahoo,” said Balogh of the new homepage. “With technology, it is always a push-pull.”

Here’s my video interview with him, talking about all this and more: