well you can upgrade right now for oblivion if youfeel you need to or you can wait for new gen cards to come out and lower prices and get a 7900gxt 1 gig
lol i just bought a 7800gtx w00t! now i need to get an agp upgrade for my bro comp... he has a 6200 agp, was thinking about getting him the 6600 or maybe 6800. we will see