jake_the_fake1 on 17 April 2013
Here's a question to your question which will give you my answer; Is the Wii motion controls the future of gaming?
BTW, Nintendo with the release of the WiiU have already answered your question.
As for the Kinect key purpose, I think it'll be mostly used for the OS navigation, make it easier for the casuals out there who know how to swipe with their fingers, and now they can swipe with their hands to navigate the 720 OS and choose their non gaming goodies like ESPN, Netflix, Huluplus, ETC, this is why it'll be a requiremt to always have it plugged in.....sure some devs including Microsoft will make some games using it, like they have now, but it's not exactly it's purpose in the 720.
