I just want to add my 2 cents to the discussion, mainly the RAM requirements. I have 2x1GB now and I can monitor RAM utilization from my keyboard, when I play battlefield 2 I hit nealry 80% utilization, incluing the OS, AIM, and Firefox, etc. So it is really not surprising to see that we are encouraged to have 4GB for gaming. I have had 2GB for3 years now, and I keep noticing how much more demanding the games are becoming on the system as a whole.
I for one, am looking forward to Vista. I want to see how MS supposidely integrated alot of stuff, all the metadata, document prefiews w/o opening the actual file, one-touch game updates, and other nifty things. There are also a few hardware devices that are supposed to alunch with Vista, the main one that comes to mind is Hybrid-Harddrives based on flash and magnetic disk storage. DX10 sounds promising, and with the arrival of Halo 2.... I'm screwed, I must upgrade... good thing I can get it for $5 at my university!!!!!