I believe the touchsmart is not a multi-touch surface which would make it not so useful to upgrade from a midi-controller to this. If you are really interested in touch surfaces, you can easily make one with a projector and an led.
Here is the complete tutorial, with a link to the software.
youtubeDOTcom/watch?v=5s5EvhHy7eQ
and if you dont know Johnny Lee yet, I suggest you watch his videos, he is a brilliant researcher.
But none-the-less ive been awaiting multi-touch monitors to flood the market but for some reason they haven't yet... In japan, on the street corners they have multi-touch flat screen tvs as maps for you to use and find where you are trying to get. Prettty cool stuff