On the 360 demo I have noticed slight slowdown during bails that enter the 'hall of meat' (or whatever it is called).
Well people seem to be saying there are framerate issues with the PS3 demo, if you're talking features though, there aren't any that I've heard about.
Also, I can't for the life of me remember how to do the slow mo flip tricks, despite playing the first game for bloody ever when I got it.