Here's a Q and A interview with the nVidia's Senior PR Manager. It looks like those with ATi cards are going to miss a lot of eyecandy, as I think we already new. Read the whole review here.
I'm sure it has nothing to do with the fact they are running in FX12, and sometimes in FP16, while ATI pixel prescison will be fixed FP24... Doesn't take a rocket scientist to figure out which one will be quicker....w/ or w/out ultra shadow... I am looking forward to this game coming out...if not for the actual game, then to lie all this conjecture to rest