The trick, it seems, is that TAT have employed some aspects of 2D UI design in what is a decidedly 3D concept. Moves aren't arbitrary, and input isn't wasted—as far as the user is concerned, this behaves a lot like a "flat" interface might, just with screen transitions replaced by movements in a 3D space.
As you've probably guessed from the reference hardware and limited demo, this thing isn't quite ready for primetime, nor is it tied to a specific product. That said, it's not totally pie-in-the-sky. TAT's Paul Blomdahl told me:
It's not a fully functional UI (or usable for that matter) but we're trying to hint a little of what future phones we're working on will be capable of.
Future phones you're working on? You tease! [TAT]