It will get you in the door but it won't put you at the front of the line. The 4670 is more of a multimedia card in that it gives good performance over most things, but when it comes to games it just gets you in the door. The lower the resolution you are playing at, the more you will be able to turn up the graphic settings, but you will want to leave AA and AF off, for the most part. It is a good card if you just need something to get you playing games at "OK" graphics.
Is this a general questions, or are you planing to make a purchase? If so, list your specs, what resolution you will be playing at, what games you intend to play, and your budget.