I still use Windows XP and will probably continue to do so even though I bought Windows 7 Pro to try out. For me the reason is I don't like the new interface, it's total eye candy with too much flash trash. Now I like the MAC interface but WinVista and Win7 seem like flash trash without substance. I bought WinVista Ultimate from a friend that worked for Microsoft for DX10 but never used it, so Win7 may end up with the same fate. Everything I read about DX10 was less frame rate with marginal gains in appearance, so no thanks.
Go figure... I was a Engineering Technician, then a HW Engineer, then a SW Engineer and always liked High Tech Anything, but the latest technology just leaves me cold. My last job with Texas Instruments was with the Wireless Computing division and the current cell phone craze seems childish to me. I just want a phone, not a wireless everything toy. But I'm sure I'm wrong about that, 50 ga-zillion people buying them can't be wrong
The 3GB limit is okay for me since I don't do that many things at the same time to need more memory. I'm even sticking with a Core 2 Duo E8600 for my next build, which is in the closet waiting to be put together. I like the lower power requirements of the C2D, the top processor is still only 65 Watts.
I can't tell you how much money I spent before I retired upgrading computers, but now I game very little (not many good pc games anyway) so the upgrade in the closet may be my last one for a LONG TIME.