I work internationally a lot. For the remainder of the year I will take a minimum of six - 14 hour flights to Asia (3 trips - 2 months stays per trip. I will take my powerbook to leave at the hotel(for heavier computing) and will carry the lighter ipad daily to pull out whenever I need to take notes (almost daily) or show a video or photos (regularly) to colleagues. The ipad will be far more useful at these tasks than my ipod touch (having 8 people gather around squinting to watch a video doesn't work.) I do not have an iphone, since I spend half the year, at least abroad, carrying AT&T for 3G has never made sense when I would use it so little. Now, when I go on vacation with my family I can buy it just for the month. I will get the 3G model just for the 1 to 2 months a year I will get the monthly plan. For vacations it will be the only device I will need to bring, not the heavier Macbook Pro.
I can also leave it as a digital picture frame when not in use. Will also play/use a couple of the apps that I currently have on my ipod. Ical will certainly be a more pleasant experience. I've read about a dozen books on my ipod touch so far. I find it manageable, but will be much better on the larger screen. it will also be a great portable DVD player/book reader/game player for my 7 year-old daughter when trapped somewhere (car, in a line, shopping, etc.)
Version 1.0 will be a benefit to me starting right away for the things it can do and do very well. (will be great for those long plane rides.). But who knows, maybe I'll pass this down to my daughter and get the next generation as well.