Hi,
I can only supply my personal feelings here, I hope that is what you are after.
1. Xp is cheaper.
2. There are fewer resources available now for 7 but that will change.
3. I think they are about equal, in most areas, and each is faster in some areas.
4. XP has been reliably breaking down for years, give 7 a go and it may be better or worse.
In summery, I am staying with XP as my every day OS, but I am trying to keep 7 up to date and play with it every now and again.

Well XP wont be supported for much longer.

Secondly, its hardware support SUCKS. No native IPV6, No native Wifi, No native SATA.

Would not recommend for new builds. Its just too old now.

win7 all the way, no if's and's or but's

Many games that run on XP will not run on Win7. So if you are a big gammer and like the games you are playing, then stick with XP.

That's just the nature of game-development cycles though - two-to-three yrs max usually. Games which were developed not long before Vista hit the ground should be OK in Win7. If seriously attached to an XP-only game, look to see if your CPU s'ports XP Mode. If so, installing a higher SKU of Win7 will allow extending the life of those games for now.

Soon most games wont run on XP due to it not having DX10. Current gen games tend to look nicer on vista due to them being able to take advantage of this.

Noooooooooooo. XP mode is horrific for games. Really poor performance because it doesnt do 3d acceleration, instead using a truly terrible emulated video card.

Very true, but most games which have never moved beyond XP are not what you would call GPU intensive (a few exceptions I know, such as Oblivion). In most cases, even the emulated GPU in XP Mode is sufficient for those (let's call them what they are... ) legacy games.

If really attached to an XP-only game - which is truely GPU-intensive - take the dual-boot option. Win7 is by far superior to both XP and Vista, so use for every-day use, and keep the second install for those heavy-duty games not suitable for XP Mode.

Yes but most people will buy an upgrade licence for Win7 and so not be able to do that.

not if they wanted to do a dual boot with winxp