It took both companies, what, 3 years to finally come up with competition to the Wii that no one wanted (On the 360 or PS3 anyway)?
Maybe I really missed the boat, or an entire naval fleet, but I don't remember anyone really pining for this.
Adult gamers, the demographic for the PS3 and 360, seem to be happy with their controllers.
I would assume that anyone interested in this technology and the type of game behind it would've bought the Wii by now.
I don't see this working too well on adult games, maybe a few, but not enough to make it very popular.
That said, I'd choose the Kinect, use it for whatever title it might actually work well for.. once, and then put it away forever,it's at least attempting to do something different, not just force you to use a new controller in a silly way, already done by someone else (and probably better) with a library for it.