Type on it (it's like a giant trackpad), or put down two fingers at once, and it's a mouse, or more fingers, and you can macro gestures.
The incumbent weight of keyboards/mice will keep them around for a long while to come, but this is still coolio. Imagine combining it with that laser-projected keyboard for palmtops. Or Powergloves.
It's enough to make Jaron Lanier spoo.