So I've finally gotten around to playing the PS3 demo today...and yeah, I can definitely see the framerate drop. It's rather unfortunate. I don't, however, see the blurriness everyone is talking about. Aside of the framerate problem it seems pretty much identical visually to the 360 version from what I can tell.

I am however curious if both versions are identical in content, as in this demo things are actually happening differently than they do in the 360 demo.