I mentioned this in another forum, but why couldn't a laptop have two screens?
A main output screen as it is now, and a full keyboard sized iPhone-like touch screen input replacing the keyboard (a bit like the TouchStream from Fingerworks, but with an actual screen). It would involve true "touch typing" - probably not to the liking of some, but the applications would be endless. The screen would be infinitely customizable for whatever input you need and would get rid of the need for a touch pad altogether. Would obviously be a bit more expensive than a normal keyboard, but likely not that much given that a smaller touch screen is included in the iPhone.