touch-sensitive iPod would be something that would be very believable.
However, it is not yet clear if we will see a tablet device, a full screen iPod, or a combination of both. Nonetheless, many points of the touch screen is a major revolution.
Check the following to see the video features:
NYU Media Research Lab jhan ~ / ftirtouch / multitouchreel.mpg
Also here'sa link from the Apple patent application on the United States trademark on the site:
The regime based graphical user interface for touch sensitive input devices.