I just updated my system to Window 7 64 bit and had some mixed emotions about doing it, mainly due to the back and forth I've seen. But I come to testify today, that i indeed just ran through a full 30+ track session with Pro Tools 8.0.5 on Windows 7, with no hiccups!
I did run into some trouble installing it. As long as you run the 'setup' file on the dvd 'as administrator' you'll be fine. Go to Pro Tools LE 8.0.5 Update for Windows and download the 8.0.5 update and run this 'as administrator' once it's installed have fun....at least I did.