I've played with one. The first thing that struck me was that it was a lot smaller than I expected - no bigger than a large office laser printer or a coffee table. I was expecting a car-sized monstrosity based on the press.
The multi-touch interface was great. I really think that might give keyboards a run for their money when it becomes cheap enough to be commonplace. Or maybe it will relegate keyboards to the status of a secondary input device.
I dabble in photography so I was happy to play a bit with the image handling. Move, rotate, zoom... all very intuitive without having to wonder how to work the interface.
