you can run it on extreme.
i have:
i7 920 @ stock
6GB DDR3
ATI HD 5850
and i'm getting a solid 50 fps at "extreme", which is max. damn consoles.
at 800x600?

c`mon guys - it is really important to specify the resolution you are using...
@offtopic - i bet there are a lot of morons on this forum who cry about DX11 and they dont even use 1080p resolution...
@ontopic - fraps is the best way to see the fps ingame
i have a 1920x1080 hd lcd 21.5" asus monitor and is capable of 1080p (HDMI)