A touch screen would work very well for me. I've tried out the one on the t4i and found it to be very useful in many cases. Certainly, buttons won't go away, but in liveview, being able to just touch the eye of your subject and have the camera instantly focus on that spot is very handy in studio situations. I'd love to see it be able to work from a large screen monitor tethered to the camera in the studio.
I have very little feeling in my fingers, and don't always know which button, if any, my finger is resting on. I even have difficulty with the shutter button.