It depends on what you play and at what resolution. I'm leaning towards recommending just waiting to see what new hardware comes out.
I play RIFT, League of Legends, Guild Wars 2, lots of steam games. I just play a lot of games. I try to play at 1280x720 but if it the games textures don't scale well, or look too crappy for my tastes I just play native 1680x1050.