Microsoft revealed yesterday that Windows 7 will include Microsoft Surface technology to take advantage of the input abilities of touch screens. The keyboard/mouse input devices are an unnatural and therefore less usable and less productive method for interacting with computers. Touch screen technology is a step away from the attached input devices that make computers much harder to use than they need be.
Ultimately, I think the future of computer interaction will include some kind of motion-capture technology so we need only use our natural gestures to manipulate technology, doing away with the input device altogether. The "killer ap," though, will be the one technology that has thus far proven far more difficult to perfect: speech recognition. Once speech recognition is ready for prime-time, we will see a leap-frog effect among all sorts of technologies because it will make everything work infinitely better.
Here’s a demonstration of Windows 7 with Microsoft Surface built in: