Well, I agree that I could have stuck with my gtx 260's a little longer, but I actually have a logical reason why I decided not to. I actually have three gtx 260s. (Long story, but the short version is that I can't actually USE all three gtx 260s because of the way that the motherboard lines up with the slots on the Antec 1200 case...) Since the gtx 260s are an aging card, I figure that it is going to get increasingly hard to sell them. Right now, I think I can get about $100 for each card, but if I waited another year or more I would have a very hard time finding buyers for them, without selling them for close to nothing. Given that I could get a huge performance boost by selling my cards now, I decided to cough up the extra $170 and get the crossfire AMD 6950s. (When I say $170, I mean the $470 I spent on the new cards, minus the $300 I'll probably get from selling the old ones). I thought about getting some of the other cards on the market, but after seeing the newest anandtech review for the gtx 590, and noticing the really good performance that was being offered by crossfire AMD 6950s, I decided to look into that option. Since you can get each 6950 for about $235 right now and crossfire them to get better performance than the $500 gtx 580 and equal performance (in many cases) to the gtx 590 and AMD 6990, I decided that video card performance had finally improved enough to make a performance improvement viable, without spending a ungodly amount of money. I've had my gtx 260's for almost three years now and have been extremely happy with them. I tend to keep my video cards for a fairly long time, but I do upgrade when I think that videocard performance has improved enough to make the cost worth it. In my opinion, shelling out $170 for the new video cards is worth the 70% (or higher) increase in performance.
On a random funny note, I found an old q9450 that I had in its box in my closet (from when I upgraded my system to a core i7) when I was looking for my third gtx 260. I also found 4 gigs of ocz reaper 1066 mhz ram. I figure I can get at least $100 for the processor and $50 for the ram. Between selling my current videocards, the cpu, and the ram, I might not end up having to pay ANY money out of savings for the new cards.