I see CNN's election map in 2012 in your future

But will it play Doom 3?

So, if I give it the old middle finger, does Windows shut down?

Yes and no - being able to swipe and prod at the screen brings a physical aspect back to using a computer. Sitting entirely motionless probably isn't a very motivating way to work, so mixing it with motion and gestures might be a good thing.

It looks cool, but their posture looks pretty tiring and I can't see this as being terribly intuitive.

Tools should help to make things easier, not cumbersome, awkward and impractical.