I've got a new quad-core 2.4 gighrz machine with 3 gigs of ram, even with everything in Vista changed to make it "look" like windows 2000, it's still WAY slower than even my old P3 with 128 Megs of ram running win2k.
Plus the video editing software I use doesn't work on Vista, and by the sounds of it, the company will only be making OS X versions in the future so it never will run on Windows again... other than old versions.