A lot of games will emerge this year with tracking as part of their controls. I don't know if it will catch on but it would be welcome as an optional extra.
It's been known about since this guy made this
http://www.youtube.com/watch?v=Jd3-eiid-Uw and very few games have bothered to incorporate it so that tells you something.
I'm working on face-tracking and 3d interfaces myself but it's more musically orientated.
http://www.youtube.com/watch?v=dubjRZRMj4M
Game developers know that if you are going to make a serious game then users are not likely going to sit there for two hours bobbing their head. It's more of a novelty type thing suited to party games or arcade machines.
My current project combines face-tracking and hand motion tracking to manipulate a 3d environment. If combining the two actually works well enough then I might pursue it further. But frankly a 2d control system works just fine and anything more is not going to be a religious experience. I'll see what I come up with.