From what I understand of the Vista's use of your video memory, as long as you have the full direct3d accelerated desktop/explorer turned on, you'll suffer a 10-15% ish hit to your gaming performance over XP. I don't know, but am fairly sure that DX10 will be released for XP, even if not officially somewhere like Guru3D.com will eventually have stuff like that. Tho my current hardware isn't even DX10 compatible, I'd have to get a whole new rig and I don't see that happening for some time.

I think most of the new features of Vista are very much Maccy in their origins...I don't doubt there are changes to the OS fundamentally, but most changes seem to be UI focussed, making it easier (different?) to navigate, easier to handle media in most forms (MP11, IE7), better looking, more up to date, etc. As everything works on my XP PC now, that isn't a particularly good selling point either. I also think IE7 is horrid, I don't like it at all. I'll be sticking to IE6 while I can and Firefox thereafter!

At work, we're happily running Win 2k clients and servers. We're going to be upgrading sometime this year, most likely Summer, and will be going 2003 Server/XP clients. There's just no benefit to be had from an organisational perspective by going that extra step. The cons however are numerous...I think Vista does many more things differently than Win 2k compared to XP & 2k, which would alienate all general admin staff who spend their days playing with Word & Excel. The hardware requirements and cost of the OS license are more expensive, and as others have mentioned, it does take a little time after a major OS release before the first large batch of bugs is addressed.

In time Vista will become the standard OS as companies like Dell, HP et all sell it pre-installed on their machines. Some businesses will inevitably upgrade, and there are some people/companies that must always be running the newest, latest thing. But 2k and XP, XP more so, both have a long time ahead of them with a huge, existing user-base. I have no interest in what Vista currently has to offer, and it'll take more than costing me 10% gaming performance for a s****y desktop UI to upgrade...especially at those prices!!!

PS. If they say "Bioshock" coming out this year won't run on XP I may well reconsider!