Why are all the motherboard manufacturers putting the socket so far right. ;_;
Honestly, I don't see games needing anything beyond an overclocked Sandy Bridge processor for at least another 5 years. There are still barely any games that require quad core, and the ones that do support quad-core barely need anything more than a 4 year old Q6600. Hell, I bet even an overclocked Q6600 will be enough for just about anyone for quite a few more years.
The only reason to upgrade to a Sandy Bridge, for gaming related reasons, right now is:
1) Making unoptimized single-core games run faster (SC2, NWN2, etc.)
2) Get better speeds out of emulators (PCSX2, Dolphin)
Outside of those two needs, I can't really think of any multicore engines that need anything more than a Q6600 @ 3.6GHz to run over 60fps. Maybe Arma 2?
TBH, I used to think that, but I'm starting to think otherwise. Like I said, there has been little reason to upgrade a Q6600, a 4 year old processor, until now. Upgrading CPUs on the same motherboard is a thing of the past. CPUs are not advancing fast enough, and neither are CPU needs. The only benefit would be if you want to go from low end to high end in the future...but that's not the case for most people.
It's really not much cheaper to go AMD at all. The 6970 is bested by the GTX 570. The only real way to save money going AMD is getting a 6950 and flashing it to 6970. You'd only be saving $50 in the end though.