After a long silence, Microsoft Windows chief Steven Sinofsky is talking, the Windows team is blogging publicly about Windows 7, and there are rumbles that Windows 7 might actually be demonstrated at a conference this week. But is Microsoft actually saying anything?Not much. Here's what we learned, and what I expect:

Don't look for too many specifics just yet. In both Sinofsky's interview with CNet and Microsoft's own blog, Microsoft did little in laying out what Windows 7 will really look like. "We're not ready to discuss specifics for Windows 7 just yet," Microsoft blogger Brandon LeBlanc wrote in a comment to Microsoft's blog. From the Sinofsky interview, I gather that Microsoft won't be talking until features are set, a la Internet Explorer 8. That said, the blog and interview note that some partners and enterprises are getting an early look at the future.

There may or may not be a demo this week. There's a report from blogger Long Zhen (who's broken some interesting news before) that Microsoft will be showing Windows 7 at the Wall Street Journal's All Things Digital Conference, aka D6, today. One source close to Microsoft told me that what the company intends to show at D6 isn't necessarily Windows 7, but instead future innovations that could be included in Windows. That gels more with my thinking that the Professional Developers Conference later this year would be the optimal time to show off Windows 7 and potentially release a first beta version.

Expect Windows 7 in late 2009 or early 2010. Sinofsky said the OS would be out "three years after the general availability of Windows Vista." This isn't really news, as Microsoft's said the same thing previously, but it's worth mentioning here.

Windows 7 will run on the same hardware as Vista. By the time Windows 7 is released in 18 months or so, companies will have likely upgraded many if not most of their PCs to a level that will run Windows 7 with no trouble. This tells me that customers buying new PCs but still running Windows XP (read "plenty of businesses") will be able to wait for and switch to Windows 7 if they want just as easily as they could to Vista.

Windows 7 will support the same apps and devices as Vista. That should be great news for Windows customers, who hope to avoid the incompatibility fiasco that was the initial Vista launch. Just as the hardware requirements, this should make Windows 7 an easier early sell than Windows Vista. That's a big promise: even Vista SP1 has had some driver incompatibility problems.

Windows 7 isn't just Windows Vista SP2, but will have similar foundations as Vista. In his blog, Windows blogger Chris Flores calls Windows 7 a "major release." That said, the "long-term architectural investments" in Vista/Longhorn, including graphics, audio and storage subsystems, will be in place in some form or function as "foundations" to Windows 7, as well as the "memory management, networking, process management, as well as the security hardening" found in Vista and Windows Server 2008.

There's no complete kernel re-write. There's been some false speculation circling around that Microsoft will re-write the Windows kernel for Windows 7. That's squashed by both Sinofsky and Flores, but it should have been long ago. The conversation that sparked the speculation circled around a heavily stripped down version of Windows a Microsoft exec demonstrated last year that's called MinWin, which the exec said then that Microsoft wouldn't be turning into a product. More likely, MinWin will be used to help Microsoft allow for modular installations of Windows a la Server Core in Windows Server 2008. What Sinofsky says is that Windows 7's kernel will be an evolution of the kernel in Windows Server 2008, itself an evolution of the Vista kernel.