Yeah using Vista Enterprise as my work desktop for testing purposes right now. It is awesome and definaetly a big step up from Windows XP and I dont want to go back.
Still alot of problems to be worked out so 6-12 months before I would recommend using it as a primary Operating System. And for anyone who does any Active directory admin stuff be warned that the admin tools dont function 100% yet. Not all NT software functions and hardware drivers have away to catch up.
If your buying a new PC i would get Vista installed tho.