For anyone who likes to try the latest and greatest in software, a beta of Windows 7 is now available. full details with instructions on how to download and more are at http://www.microsoft.com/windows/windows7.
Whether you try the beta or not, there are at least two excellent resources for learning what’s happening with Windows 7 from people at Microsoft. The Engineering Windows 7 blog and The Windows Blog are resources where extensive info about how Windows7 is evolving is posted.
I’ve used the Windows 7 beta successfully with several screen readers including JAWS, Window-Eyes, System Access, and NVDA. Your mileage may very but I would suggest you run the newest versions of these programs if you do try the beta.