Its a gimmick IMHO and an attempt by Microsoft to shore up the massive casual market that Nintendo cracked open.
Whilst causals may think its the “bees-knees” many hardcore gamers will see this as a passing fad.
It doesn’t compete with Sony’s Move simply because MOVE is attached to both casual and hardcore markets.
I suspect the 360 will get nothing but shovel ware from Nintendo’s awful 3rd party library since Microsoft has no real 1st developers apart from RARE (but when was their last AAA title?), where Sony owns quite a number of them.
I call half a dozen good titles by next year and then it will fade.