An interface concept doesn't have to be practical to be interesting, or to make current software seem dated and flat. Exhibit A: Swedish designinstitut* The Astonishing Tribe's newest cellphone interface, which is rendered in glorious 3D, and might be brilliant.
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]