It looks interesting, but I'm afraid it won't work past casual games and limited projects (ie. the "Milo" tech demo).
I just don't see how you could play an FPS game (especially competitively), nor how one is supposed to move in a 3D space. And where are the 'pause' and 'guide' buttons located at on my body?
There is also the significant issue of living/bed room space. The video they featured had a rather large living room and I speculate that very few individuals will also have the same. I just don't see how flailing my body around will be plausible in my rather small room.
If anything, this technology seems like it would be more beneficial when in conjuction with a more traditional controller - especially the rather impressive voice recognition.