The Surface OS
I like the new Surface computers. I think they're really revolutionary. They don't have keyboards. Or mice.
My first impression is that this is the first step of getting rid of the need for every new Windows computer to be backwardly-compatible to run every Windows and DOS program that's ever been written.
Scott Guthrie said the interaction is built with WPF, which reaffirms to me the wisdom and synergy of Microsoft's overall planning and strategy. I think they were being literal when they put the F in WPF, because it seems to be a foundation that future computing will be built on. I'm starting to read up on it.
I think they'll factor out and expose chunks of functionality, like the wireless device interaction, so that creating programs for the tabletop display computer will be done for the most part several levels of abstraction above individual lines of C# (on a mock design surface in the middle of Visual Studio, I'm thinking).
But we'll still be using PCs with keyboards and mice to create the programs that run on the surface--at least for the foreseeable future.