Eyetoy was awful. It sucked at picking up movement correctly.
I almost broke my hand with the Eyetoy. Protip; Don't play the Karate Chop game in a cramped room next to a Metal Bar from a bunkbed. :(
I think Kinect should be interesting. Certain things will be odd, but otherwise I think nothing bad can come from it.
I can't wait for Fable 3 to come out with it, although, with games like that (since I haven't fully seen/read into it) I don't know how walking is done. Obviously if you walk, you'll be doing it on the spot, and it seems kinda tiring/boring to just walk on the spot in the centre of your living room.
Otherwsie though, I'm excited. :D