Games on the wii, with motion control done right is really great, and some of the new controller types eg. guitar are cool. But things like wii fit, the balance board itself is great, but I still can't bring myself to exercise in front of the TV....unless it is on a treadmill!
Natal is stupid. Controls are for reason. When i was kid, i used to pretend im driving car with outstretched hands, but now i want hold something. A steering wheel for example? Shooting with my finger? No thanks. I'd rather use some cheap plastic addon for controller making it more like gun. And what about recognizing involuntary movements? I'll scratch my head and get shot because of it? There is just very few games which could benefit from non control controls. Like Virtua Fighter. But even then would be better just to go and take kung-fu lessons.
I dont think the wii controls are a gimmick, it's just something different, the main important thing is what people do with those controls. I think people these days are always looking for that one thing they can change to instantly make zillions of dollars like "look same thing different controls" or art style or whatever. not exactly a bad thing, but the reason good stuff is good, is because it's different and good, not just because it's different.
I have a wii and at first it seemed really great. Then I ran into this problem of sunlight causing your controller to wig-out while you are trying to play during the day. They are solutions to this problem, but it would have been nice to know about it before getting shot a few times during World at War ...