This week, Microsoft Corp. went on a 24-hour marketing blitz to talk up the next version of Windows, simply called "Windows 7" for now.

Although some of what Microsoft's executives and spokespeople had to say was how much they weren't going to say and why, a few informational dribs and drabs have worked loose from Redmond.

What, exactly, do we know about Windows 7, the successor to Vista -- the operating system that if not troubled then at least, as Gartner analyst Michael Silver puts it, carrying " a lot of perception issues?"

Not a lot. Certainly not nearly enough for some of those constituencies thirstiest for details. But here's what we do know, or at least know because Microsoft's said it's so.

When will Windows 7 be released? Depends on who's talking, apparently. Early Tuesday, two Microsoft executives, Chris Flores, a director with the Windows Client communications team, and Steve Sinofsky, the senior vice president who heads Windows development, both pegged the release of the Vista follow-on as early 2010.

"We're happy to report that we're still on track to ship approximately three years after the general availability of Windows Vista," said Flores in an entry on a company blog.

"[We] will continue to say that the next release of Windows, Windows 7, is about three years after the general availability of Windows Vista," Sinofsky told News.com that same morning.

Tuesday night, however, another company executive -- the one who heads the org chart, in fact -- said different. At the Wall Street Journal 's All Things Digital conference, Steve Ballmer , Microsoft's CEO, put Windows 7's ship date as "late 2009."

The spread between early 2010, which would be the "three years after the general availability of Vista" -- that OS went into general distribution at the end of January 2007 -- and "late 2009" may not sound significant, but only a few months separated Vista's actual release from an earlier date that would have meant the operating system made it into computers in time for those PCs to sell during the 2006 holiday season.

What will Windows 7 be like? Under the hood, a lot like Vista, according to the tidbits that Microsoft tossed out this week.

Flores was almost expansive on the subject, and noted that Windows 7 would "carry forward" the "long-term architectural investments" made in Vista. "Windows Vista established a very solid foundation, particularly on subsystems such as graphics, audio, and storage. Windows Server 2008 was built on that foundation and Windows 7 will be as well," he said.

In fact, Sinofsky and Flores confirmed other like-Vista aspects of Windows 7, including the fact that the new OS will be released in both 32- and 64-bit versions -- there was some speculation earlier that it would be a 64-bit operating system only -- and would, as Flores said, run on the same hardware as recommended for Vista.

Has Microsoft said anything about specific features it plans to ship in Windows 7? A little, but only that. Tuesday night, Microsoft demonstrated a touch-screen feature that the company said would be integrated into Windows 7.

The feature, which incorporates technology Microsoft debuted last year as its Surface project, appears similar to the gesture-based multi-touch tools built into Apple Inc.'s iPhone and MacBook Air, though on the latter the touch is limited to a larger-than-normal trackpad, not the entire screen.

Nothing else? The sessions list for the upcoming Professional Developers Conference , scheduled to run Oct. 26-30, has a couple of clues.

One session, says the current list, will focus on battery life -- presumably batteries in notebooks first of all, but also for other mobile devices Microsoft hopes to get Windows 7 into.

"Windows 7 provides advances for building energy-efficient applications," says the write-up. "In this session we will discuss how to leverage new Windows infrastructure to reduce application power consumption and efficiently schedule background tasks and services."

Other sessions at the conference will tackle such Windows 7 topics as "Graphics Advances," "Touch Computing" (but we already knew that), and "Web Services in Native Code." That last sounds intriguing, considering Microsoft's push-push-push on its "Software + Services" concept.

The OS, says Microsoft, will include a new networking API (application programming interface) to support building SOAP-based Web services in native code. "This session will discuss the programming model, interoperability aspects with other implementations of WS-* protocols and demonstrate various services and applications built using this API."

Will Windows 7 sport a new kernel? Nope.

Last October, a Microsoft engineer revealed that the company had 200 programmers working on slimming down the Windows kernel for Windows 7; he dubbed it "MinWin" and said it would sport a memory footprint less than one-sixth that of Windows Vista's kernel.

Last week, though, Flores and Sinofsky both said Windows 7 won't sport a new kernel. "Contrary to some speculation, Microsoft is not creating a new kernel for Windows 7," Flores said.

Sinofsky put it differently. "The key there is that the kernel in Windows Server 2008 is an evolution of the kernel in Windows Vista, and then Windows 7 will be a further evolution of that kernel as well," he said.

Will Windows 7 be a major or a minor release? The parsing of these adjectives is important because post-Vista, Microsoft said it was planning to update its operating systems on an alternating major-minor basis, with the major upgrades -- think XP to Vista -- every four years, with minor ones in between. A good example of a minor upgrade would be Windows XP SP2, which though called a "Service Pack," was unlike any other SP in the new features and capabilities it added to the previous OS.

Trouble is, Windows 7 sounds like a minor upgrade, but Flores and Sinofsky called it the opposite. "Another question we often get asked is whether Windows 7 is a major release," said Flores. "The answer is 'yes'."

Sinofsky used the adjective "major" six times during the interview with News.com, as in "major undertaking," "major release," and "major and significant release."

Another clue: Windows 7 will use the same device driver model as Vista. That OS, remember, required new drivers for all hardware -- a disruption that even company executives struggled with, as some said in internal e-mails released earlier this year as part of a class-action lawsuit against Microsoft.

The mixed message -- is it major or is it minor? -- confused at least one analyst. Michael Cherry of Directions on Microsoft. "To me, a 'major' update means major changes to the core functionality of the operating system." With Microsoft saying it was going to build atop Vista, not start from scratch, Cherry said he wasn't getting the impression that core functional would significantly change.

Why is Microsoft playing it so close to the vest on Windows 7? Good question.

Microsoft essentially said it learned a lesson from Vista, when it promised features -- such as a retooled storage subsystem called WinFS -- that it ended up yanking from the operating system as development dragged and deadlines grew near.

"We can significantly impact our partners and our customers if we broadly share information that later changes," said Flores in a separate entry on a Microsoft blog Tuesday.

Analysts, including Directions' Cherry and Gartner's Silver, said much the same. "They talked more publicly about Vista, but in the end that didn't make them a lot of friends," noted Silver earlier this week.

So, is Microsoft dumping Vista? No. Company executives, including its CEO, came to praise Windows Vista, not bury it, even as they touted its replacement.

Steve Ballmer defended Vista Tuesday when he talked at the All Things Digital conference. "Vista is not a failure, and it's not a mistake" Ballmer said in response to a question. Nor is Microsoft throwing in the Vista towel. "Are there things that we will continue to modify and improve going forward? Sure," Ballmer added.

Flores, meanwhile, trumpeted Vista's sales numbers. "As of March 31, we had sold more than 140 million Windows Vista licenses," he said.

Computerworld