An AMD HD6970 or Nvidia 570 would be a nice step up for your setup.
The CPU will be a bottleneck at lower resolutions, but at 1920x1080 a beefier video card should help quite a bit. Also, a video card can be carried over into a new build if you decide you need even more processing muscle.
All Settings Maxed is going to take a lot todats games can eat even high end video cards for lunch and still want your CPU for a snack later, I would think you have two bottle necks your CPU and your graphics I would go a single GTX 570 or 580 (if your pockets are DEEP and a I5-750 for a CPU. for a bit more you could go I7-930 and get room to Grow to SLI later.