Just saw the developer release last week, Thursday, MS Release for the public but they rolling it out earlyish to try and avoid the server crashes of last week.
I love it, Some getting used to and some features still not yet come to it that were not ready and some bugs but it is more solid then Vista already and just dam nice to use, The task-bar is brilliant, Takes the good bits of the windows bar and what mac does and combines them well. They finally have something to work with now.

http://www.microsoft.com/windows/win.../download.aspx