It's always puzzling to me how Apple can take things that others have done and present them like they're a new thing -- no, that's not the puzzle, everyone does that, what puzzles me is how they get away with it. People sometimes say they take things that have been done badly before and do them well, or take things that were boring and do them sexy, but even that's giving them too much credit. Others have done the same ideas just as sexy, just as polished, and just as well. There's no explanation beside the sheer weight of reputation and marketing muscle, though admittedly that only works because they also go to such lengths to make sure they are always done well, and done sexy.
I find the newly-announced and already-overhyped iPad mildly interesting, but not significantly more so than any number of previous attempts in the same direction. What makes it intriguing is that it seems likely to be a lot lighter and thinner, and the price point is surprisingly good. But it all comes down to what you can do with it. A pretty web browser is a great thing in itself... but if you can't keyboard on it without clicking it into its keyboard dock (which ties you to a location and some extra cost) or laying it flat on a desk (making it ridiculously hard to view) or thumbboarding it (making it barely better than my phone), that eliminates way too many possible uses even for the web browser functionality, let alone any kind of productivity application.
So what does that leave? An overgrown PDA too big to fit in your pocket, basically. It might be nice to watch video on, though I doubt I'd want to hang onto it so that means I have to put it in a stand or something. But it'd be terrible for reading eBooks for the same reasons I've previously noted, that eBooks are one exception to the rule of convergence, since screens that are good for video or interactive content are bad for eBooks and vice versa. (Thus, the iPad is another threat to the advance of eBooks, since a lot of people will insist on using it as one, then bemoan that the eBook concept is flawed since it's uncomfortable to read them.)
The iPad looks like a solution in search of a problem. It'll all come down to the software, of course, and how quickly the massive army of iPhone app developers start making variations specifically for the iPad. But while there's a billion iPhone apps, once you subtract the ones that show a bobblehead of a cat which makes a chirping noise and does nothing, and similarly useless things, the number of apps that do something you actually need done is not that great. But there's just so many apps that you can always find something to do, and probably something to do what you want. How well will that adapt from your pocket, where all you need is a Swiss-army-knife level of quality and applicability to the task, to a tablet, where you need to have something better than your netbook or laptop to be worth it, and enough better than your phone to make it worth dealing with hauling it around?
It all keeps coming back to input methods. Multitouch is a nice gimmick, but like Graffiti, and voice recognition, and touch screens, and virtual keyboards, it's not the solution we need to take something like the iPad (or any other portable technology) into the indispensability that it wants to reach. The ugly truth is, QWERTY still rules only because we don't have anything better yet, at least not something you can put on a battery-powered device you can carry around and which can be manufactured at consumer-friendly prices. Every step we take towards portable technology will either ignore QWERTY at its peril, or incorporate it and thus feel like an incremental improvement only, until someone finally really beats it.