I have turned everything to low, no HDR and am seeing about 12-20 fps.
Heres the odd bit looking straight ahead not too bad turn head about 45 degrees and the frame rate drops noticeably. Turn a further 45 degrees to either side and it smooths out some. I have a feeling that my video cards are at the very bottom of the specs. 2 nvidia 8600gts in sli. Oh and I get the same slow downs in vidoe in external view as well.