Tested and running Win 7.  Works like a charm on my iMac 24″, which also runs Ubuntu 9.10 and Mac OS X Snow Leopard.
All in all, I would say it's probably the best MS has come with in the last years.  Problem is still the price versus the functionality additions (6 versions?).  I did buy it only because I'm still at the university so it was 40$.  But I would never pay for that last one otherwise (330$ for the professional version I own).
Cost me 70$ for all my Macs to have latest update which is pretty neat.  And 0$ and 5 minutes of tweak for full functionality of Ubuntu.  If you do the maths….
Honestly though, it all sums up to one thing: It's an operating system.
I personally work on Mac and Ubuntu and play my games on Windows.  It's just a computer in the end…