Too slow, too much eye candy glued on to make it look like OS X. Definitely features I don’t want on my dedicated gaming machine.
After running Vista Beta 2 for a week, I completely reformatted and reinstalled XP w/SP2 from scratch. With the SATA hard drive, it runs like a bat out of hell.
I’ve ordered a ASRock 939Dual-SATA2 motherboard, so I can move over all of my current components and then just upgrade to a PCI-E video card (I’m thinking of a 7600GS) later. This way I don’t have to upgrade the motherboard and video card at the same time, as the 939Dual has both AGP and PCI-E slots. After that, I don’t see a need for any upgrades for the next year or so; I’m already a year or two behind “bleeding edge” for the games I play (Far Cry, Half-Life 2, Battlefield 2, etc).
For my Real Work, I still have the Core Duo-based 20″ iMac in my office.