Chris Pratley, the head of Microsoft's Office Labs, gave the PICNIC audience a peek into the future they envision when planning their products. What is that future? It was encapsulated in the above video that they made a year ago. Some of the technologies (Augmented Reality and realtime language translation for example) have already come to the fruition (and they are going to need to make a new video soon before it all happens).
An initial viewing of the video shows that Chris and his team (and Microsoft in general) are concerned with screens of all sizes - from 10-foot wallscreen to 2-inch boarding passes. In all of these displays they imagine that the screen is also the interface. How will the current interfaces scale? For larger ones there is a concern for how to keep the controls near the user. For smaller ones there is no room for controls. The screens will be maneuvered by making the back touch sensitive (called Nanotouch). One of the key Microsoft researchers in this area is Patrick Baudisch.
These interfaces are possible now. I have played with Nanotouch devices at MSR -- some no larger than a 50 cent piece. And not only are the larger displays possible, they will potentially be cheap. The picture below is a new MSR project that shows one method for creating large scale screens cheaply. It uses a pico projector that is the size of the phone and a specially cut piece of plexiglass. The image below shows a display that is only ~2 feet tall, but you can imagine this working at 10 feet. Chris stated that the size of the display is bounded by the projector's brightness and that pico projector brightness is doubling every 9 months. In the future cameras can be added to allow for gestures on the interface.