I know how you feel.
I have a 4200 X2 with a 7800GTX and I still get stuttering.
I found that dropping the settings to low fixes it. Its really not even noticable at 1680x1050. The only thing I have to keep up is shadows as the low quality shadows give me a headache with all their shimmering.
I'm really disapointed by this games performance. Oblivion seriously runs better on my PC with maxed settings than this game does at medium settings.
I can appreciate the amount of details the devs put into all the models, but frankly, its just pointless. You really cant notice it at all when you have the camera moved back far enough so you can see where you're going.