I think it's all been said by now but I'll throw in my 2 cents. The Wii is a great concept but tough to create fun games for. The same for the Playstation Move and Kinect. There are examples of successes, like the dance kinect crap. The Wii was popular because Wii sports was so engaging and adults could join in the fun. But Nintendo continues to let developers push out crap shovelware diluting their brand image. My idea for what will work in the future? Combine the technologies of the Wii/Sony Move with Kinect, and add in some virtual reality goggle that allow for peripheral vision. Of course this won't happen anytime soon.
[mod edit: unrelated video removed.]