It seems more like something that would be convenient for a parent that is forced to buy it for their kid for Christmas because they saw it on TV and it looked cool rather than an actual investment, especially noting the library.
Like the Kinect library isn't entirely bad, there's Gunstringer, Child of Eden, Fruit Ninja, and apparently Dance Central is a really fun party game if you're willing to be a bit outgoing (or drunk), but a lot of what interests me about it seems something worthwhile in a $50 accessory, not a $150 one.