Some use cases:
- Recipes using Epicurious - who wants a full blown computer in the kitchen? - Browsing instantwatcher.com and adding movies to your Netflix queue from the sofa. - Reading your newsfeeds while you eat breakfast. - Any browsing related task where you don't want to leave the room (checking weather forecast, google searches, booking an airline ticket, reading email).
Really, the wife and I have had an iPad for 1+ years and we still get a few good hours a day of use out of it. I've had a Sharp Zaurus and other devices before and they all ended up in a closet or drawer after a few weeks. The tablet PC is very useful because it does fill that niche in between wanting to go to the office and get on the desktop tower or trying to look something up on your smartphone.
- Watching movies someplace where you don't have a TV
- Looking up something on the Internet similar to above where the smartphone is simply too small to use for the experience
- Games for the kids
- Entertainment on planes (reading, games, movies)
Had mine 6 months and can't imagine how I lived without it now.
Use cases:
-Torrent textbooks. Now you have all ten of your heavy textbooks in one thin compact device. Also, they're now free.
-Sitting in lecture and the professor says something that you'd like to wikipedia. Why haul out a clunky, sleepy laptop when you can do it quickly on your tab. Also, you can read hacker news quite conveniently when the professor is 5 minutes late.
-Write notes. Also, there's got to be some app that let's you draw on your screen so you can record diagrams as well.
-Physically convenient. You can almost completely replace a full backpack with a one-handed 7-inch slab. It also plays music so you can turn on that rain ambience mp3 while you lay on the campus lawn reading any of the millions of ebooks that are now at your whimsical disposal.
The other big reason is as an eReader.
I just don't find the web, virtual keyboard, and other apps to be interesting enough to grab me if there is a desktop/laptop alternative. And their too large for me to take everywhere I take my phone.
With that said, I have little doubt that touch-based computers will come to dominate, although I think convertibles will actually turn out to be quite popular. Unlike cellphones, an actual keyboard on a tablet is HUGE win.
If that's their plan, it is going to have to involve a time machine because there are at least 3 other Honeycomb tablets that have been released already: Xoom, Eee Pad Transformer and the Acer Iconia.