I will stay with the older versions of Windows no matter how good Vista gets, Microsoft is just trying to force people to buy there sh*t operating system, it's a complete waste of money if you ask me.
Windows Vista is worse than all the other versions due to it's very high system requirements, and this will be made worse by them trying to emulate DX9, sure it may be a bit more secure but who wants a operating system that will have problems playing DX9 games and such high system requirements.
All Microsoft has done is given it a paint job and fixed a few bugs, also it looks to me they have added a pile of crap that no one wants that will just slow the system down.
Microsoft are digging there own grave with Windows Vista, no one in the right state of mind would use such an operating system, Windows XP was bad enough, my advice is to stick to Windows XP what ever Microsoft do, or dump Microsoft once and for all, use Linux or BSD.
-The Chicken Man