Stephen over at UX Evangelist has posted the first screenshot of Windows 7 M3 (build 6780). It's just Paint, but as you can see, it's got the Office 2007-style ribbon UI, which is interesting:
Sadly, it looks like it's from a virtual machine. I'm curious to see what Aero looks like in this build.
Nice job, Stephen. Let's get some more pics out there. :)