I'd suggest they make an entire computer that fit in the form factor of a keyboard, but theoretically we've already done that http://en.wikipedia.org/wiki/Apple_II ;-)
Yeah! You made me remember my first PC: an Atari 130XE. No mouse back then though only arrow keys. The one use for such device today would be to use your big flat TV as a 'smart' tv. I actually did that with an Android stick and the wireless kb+trackpath linked above. It was very useful that way but lack of muscle on the Android stick is what turned me off.
