LoL, they can make it, but who will buy it!?
i don't think that 1 million core gamers will buy it (except if they really feel they need it), or that
1 million casual gamers will instantly buy an Xbox360 for another fitness game
Natal could beat Wii or be closer if it was released at Xbox360 launch, now it's too late MS, you should have keep developing Natal project for your next console, but since it's 2015 as you are saying... : P
Wii is too popular now, it's not just Wii Sports and Wii fit, it's also SSBB, Mario Galaxy, Mario Kart, Mario and Sonic at Olympics and so on, i'm sorry MS, but Mario cannot be copied and he's too popular now!!
don't mind my username, that was more than 10 years ago, I'm a different person now, amazing how people change ^_^