I want one, and I am going to buy one.
The use for me will be to replace my small laptop I take with me on business trips I take. I need a computing device that allows me to be entertained on long flights (check), I need the ability to record audio during conferences (check), I need the ability to take notes during the conferences (check), and I need the ability to connect to the Internet and email while I'm out of town (check.) For me, it does everything I need it to on these trips, and comes with a format that is easier to handle, carry, and deal with than a laptop.
Plus, I want to be able to use it around the home and be able to connect to the Internet at my home downstairs (my main computer is up stairs) while I watch TV and such. It, to me, seems like it will be much more portable than my laptop could ever be. I foresee myself taking it to places I'd never be able to with my laptop.
When I can save up the money, I'll be going for the 16GB WIFI 3G version.