Found this the other day and although it's not exactly keystroke ready someone is pouring time and money into it. http://www.engadget.com/2012/03/26/nec-tactile-touchscreen/
It would indeed be great for Angry Birds, but I don't see how it could simulate the "HP key click" feel.
and it will still have problems with smears (from skin oils) and paralax. No thanks. Well, at least maybe it would allow you to rest fingers on the keyboard that aren't pressing "keys" at the moment-- except, OTOH, you can't feel where the keys are, even though you get a click when you press (anywhere). No, I hate touch screens.