I currently have a evga 8800gtx superclocked, but was thinking of upgrading the videocard. Would it be better to pick up a 4870 1gb card for x-mas, or wait another 6 months? Would the 4870 be that much of an improvement to justify spending the money now? the 4870 cards are a steal at $300...which is why I was thinking of that card instead of the gtx 280 ($450)

OK, maybe a dumb question, but when did you get your 8800GTX? Since you bought an Evga card you have 120 days to step-up to a 9800GX2 (only 90 days for other cards).

It depends on how rich you are. If it's me, I'd probably either just get the 9800gx2 or ride it out with the old 8800gtx until ATI release the 5000s generation, which should drop prices for 4000s. Just look at how 9800gx2 halved in price when the gtx200s came out. It still outperformed gtx280 for far less money. The best value is always one generation below bleeding edge. The smart money is on 4870x2 having similar drop once 5000s roll out. And since it's ATI instead of Nvidia, you can cf it. The only reason you couldn't apply this currently is because 3000s ATI cards are so bad it's not an option for high performance. The once $500 3870x2 has now dropped to $200 ar.
http://www.newegg.com/Product/Prod [...] 6814127326
Giving that the price cut trend has held true again and again, the smart money is on it holding out one more time for 4870x2.

Then you're paying $300 now, plus whatever price it settles at in 6 month. Historically, single gpu cards don't drop in value as much as x2 cards in the same period of time. But let's say it'll be $150 by then, that's $450 total.

A 4870x2 cost $520 now, and around half that much later ($260?), if trends hold true.

The advantage of 2 4870s, is, of course, you get one 4870 now, instead of using the 8800gtx. However, considering the performance difference between 8800gtx and single 4870, then the final price difference of the 2 routes, it might be more cost effective to make do with 8800gtx.

There is also the possibility of saving the second pcie slot for second x2.

What's wrong with an 8800GTX? What games can you not max or high?

If I were you, I would wait until at least the ATI 58xxx series until I upgrade; the 8800GTX is still a pretty awesome card