Positional controls, like for adjusting the ___location or rotation of an element on the screen. It's hard to imagine somebody doing 3D animation or advanced audio editing using only keyboard shortcuts, but it could be feasible with this device.
However, their video seemed to focus on gestures only. I'm not sure why they aren't demoing it for positional controls- maybe they haven't exactly figured it out yet.
I'm really excited about this and from now on I'm going to have troubles not thinking about it every time my hand moves from my keyboard to my mouse.