For those that haven't seen what Microsoft Surface is all about have a look at on10 for a demonstration of some different applications running on it.
It'll be shipping this year at $10000, so very much aimed at the commercial space at the moment, but hopefully within 5 or so years it'll start becoming more mainstream.
I want one of these as my coffee table, and we need some cool applications for it too. Like Pac-Man and Geometry Wars.
From a hardware perspective, it's a PC running Windows Vista, in a box with a projector and a few cameras which are watching the surface, so it's not a touch screen, which means you can place objects on the table and it can recognise them. Pretty neat.