Old electrics (circa 1960s) had fantastic control over key pressure and you could type for hours without feeling like you'd been drumming your fingers into a steel plate.
I have a design that uses a laser array to track finger twitches so that no keyboard at all is needed.
You want qwerty you get qwerty but you can also get your favorite game controller configuration ~ just run the trace and track program.
It should be just as easy to do a one-handed virtual keyboard operation with this design.
All I need is several hundred thousands of dollars for R&D.
For the amount of money that thing costs, I would think one might be able to manage some sort of force-feedback system. Probably using one actuator per column, plus one each for modifier keys. Using an actuator per key would be a bit too far overkill.
http://www.thinkgeek.com/computing/input/8193/