Touch Screen? Or Touch-me-Not?!

Touchscreen systems are much-hyped nowadays. PDAs that worked with the stylus, the recent advent of MotoRokrE6 in India, and I'll be a fool to miss out the Apple iPhone. You know what's lined up for you next?! Perhaps you do. For the ones who dont...
Microsoft Surface & Multi-Touch OS (by NID students Adithya Ananth & Divesh Jaiswal) along with their NaturalUI.

Hmmmm....after you've visited the sites, I'm sure you must be going 'Wow!'

Indeed its an innovation in user-interfaces. But something makes me think that it has great potential to mess up things. Not accepting the inevitable change (especially when its gotta do with a more natural user interface) is stupid, but obviously I have concerns:

1. Can the human finger be as precise as the tip of the mouse cursor?
2. How big or small can the interface be?
   
3. What about the ergonomics?
   
4. What will be the learning curve? Can the computer-user accept the change?
5. The UI looks welcoming to the non-tech-savvy people? Is it really?

Dan Saffer | UX Week 2008 | Adaptive Path from Adaptive Path on Vimeo.

I'd be editing this particular blog when more such issues come to my mind. I'd like you to comment about what you think could be the issues. And those in favour of the touch-screen are obviously welcome to prove my points wrong.