3 Microphones and 2 cameras, plus a lot of fucking genius technology to place you inside a room during the calibration, etc.
It's because the current lineup is aimed at the Wii market. Most of the Wii's games are shit like that too.
Xbox has a solid base of gamers, and they are looking to take away some market from the Wii. The initial batch of games is meant for that crowd. Think about how crazy kids are going to go for the technology and novelty - and not having to worry about remotes being flung into your TV set.
So, Wii - I wouldn't even bother anymore TBH.
Sony's offering is far ahead of it, they have better graphics, better games, a SOLID console experience and the Move is better than the motion controller available for the Wii.
The same goes for the 360, except that their approach is more unique. If you don't have a console and are looking for a full experience in gaming, I would personally recommend a 360 + Kinect. However, that is just my preference.
You will get more FPS games on the 360 vs more God of War type games on the PS3. Both very good consoles, it's up to you which to choose.