Sorry, but I disagree.
For ages I have sensed a gap in the interface between myself and my computer, a gap that could be bridged with a touch-screen.
The touchscreen technology that has finally arrived is exactly what has been needed: An affordable rapid response mechanism for switching between windows, launching applications, enlarging or reducing images, or centering in on locations. Additionally, it is beginning to be a means of highlighting or selecting text or screen portions and drawing or marking-up on-screen (the technology here is still in various developmental stages).
Touchscreen is almost exactly what it should be: NOT a replacement for the mouse, but an extension of the mouse for communicating with the computer.
Touchscreen is hardly in its infancy. We have using it on our phones for ages and our displays have not been ruined as a consequence. We have already internalized the general idea of touch and the possibilities it affords us. In fact, for those people who are more phone-centric than computer-centric, the biggest problem may be letting go of the touch approach and learning how to use the mouse to maximize the interface.
As we develop cheap directional microphones, or contact-mikes that pick up subvocalizations, we will even further increase our ability to integrate our intentions with the mechanics of technology by using the voice (when convenient and not an intrusion on others) for mostly monosyllabic responses or instructions (no, yes, up, down, back, forward, left, right, copy, cut, delete, paste, and so on).
It will be a sequence that flows almost seamlessly: Type a message, touch send, click on CC, speak a name or select one by tap or mouse, say "yes" or "more" for confirmation. I would bet that this is in place and working well within the next three years.