Why? So instead of carpal tunnel in your wrist you can have it in your entire arm?
agreed. outside of limited uses like kiosks at bookstores etc I can't see a need for touch screens
what I could see them do is, as perhaps a +$20 option, have that short keyboard with a touchpad added where the number pad used to be. as a replacement for a mouse. you get the multi-touch like with a laptop, eliminate a cable etc. perhaps they could even make an optional 'pen' to use for drawing programs, etc.