If your CPU i fast enough that it isn't bottlenecking your system, then any frame rate over 60 fps is just wasted on the average gamer. If you can't get 60 fps, and the first condition is met, then your problem is your GPU, not your CPU.
If the game doesn't need more than 2 cores anyway, then an i3 2100 would be sufficient if gaming was the only criteria. Anything more would be a waste, right?
The majority of the games coming out now are nothing more than console ports, anyway. Sure, we may still see a few games that challenge the current hardware, but most of the game sales are now driven by the XBox 360 or the PS3, and last I checked, console hardware was several years behind the performance curve.