Touch screens aren't new. I recall seeing them at a visitor information center while on a vacation back in 1984 or 5. The screen was part of a kiosk, which, being the little nerd/hacker I was even back then, I opened to reveal the Apple IIe plugged up to the monitor. There was a dot matrix printer, an Applewriter if memory serves, which would print out the information you selected with the touch screen and eject it through a slot in the kiosk. High tech for the time, I thought.
Honestly, I don't want to touch my screen. A mouse or pointing device is fine with me. I'd rather have something that allows me to not touch anything. Putting skin oils on a screen that I'm going to have to look at just doesn't turn me on. When it's cold, nobody's gonna take their gloves off to touch the screen, anyway. A widely-circulated story showed asians using sausages to touch their screen to avoid taking their gloves off. Tell me THAT'S sanitary.
Put multitouch on a touchpad. Invent wireless fingerpads. Use motion sensing. Touching a screen for a pointer just seems to be going the wrong direction.
Writing on the screen, a feature available for years as well, is a different story. I can see where that would be far more useful for the tablet style PC. I can also see where you'd want to have the ability to tap areas while writing. Again, though, this is nothing new.