I can think of only couple niche uses:
- replacing a notebook for people who like to sketch ideas
- replacing a doctor's clipboard
- doubling as a wacom tablet (cintiq) for designers
A touchscreen PC with no keyboard is extremely limited in utility and ergonomically awkward at best. We're already carrying around android/iPhone devices and slim, lightweight laptops--what does a tablet PC add to that mix?
Unless a company completely reinvents the idea of the tablet PC, I think these devices are destined for failure. Maybe Apple has something up their sleeve?