^Well you'd be surprised I think. A lot of programs have problems when the OS version changes (i.e. from XP 5.0 and up to Vista 6.0)...they decided to keep it the same version number (just make it 6.1) to avoid the most basic compatibility issues...Also, they've made the XP compatibility easier to access in this version. I don't think there will be any major problems with compatibility this time around.
If I die today, I'm happy how my life turned out