Student tool?

The iBookstore format is ePub, which has relatively limited layout support, making it a poor fit for most textbooks. Apple has not announced any support for Adobe Digital Editions, and non-DRM PDF textbooks are a pipe dream (feel free to solve this problem next, though, if you're up for a challenge). Also, the tiny on-screen keyboard with no support for a stylus means no serious note-taking. You can tweet and fingerpaint, but that's about it, so you'd still need to carry actual notebooks. If you were, say, going to the library to work on a paper, do you take the iPad and an external keyboard, or just carry your laptop?

Carry it to meetings?

No remote for using it in presentations, need to carry a dongle to attach it to a projector, no serious note-taking, microphone unlikely to work well for audio notes.

Errand-running?

Pretty big for holding your shopping list, no GPS for finding your way around (although WiFi-based triangulation may work in some areas), no camera for scanning bar-codes.

Commuting?

Only on a train or bus, and definitely only with an optional case to reduce the risk of dropping it (and also hide the big shiny expensive steal-me gadget).

Visiting friends and family?

"Hey, check out the new pictures of the kids! Oh, you want a copy? Hmm, I can't plug it into your computer because it will try to sync, so maybe if I plug in the SD dongle and copy it to a card from your camera, you can transfer it to your machine later. Oh fuck it, I'll just mail you the Flickr link."

Camping?

No GPS, no offline mapping, poor 3G pretty much anywhere interesting, and can't read a book after the "up to 10 hour" battery life is over.

Not an exhaustive list, to be sure, but so far, every reason I can think of to carry this gadget involves either doing without some functionality or carrying it in addition to something else, like pen and paper, a laptop, a phone, a GPS, a camera, or some of the many optional accessories. Taking notes? Add a Bluetooth keyboard or the special dock. Transferring data, including attaching it to a larger display? Carry dongles and cables. Etc, etc.

It’s 7.5x9.5x0.5 inches and weighs a pound and a half. Add a case to protect it from damage, and you’re carrying around a cookbook. In fact, you’re carrying around this cookbook. I could carry this cookbook everywhere I go, but it’s big enough that I wouldn’t do so without a good reason. Take a look at the top 100 applications for the iPhone; are any of them compelling enough to justify carrying a cookbook around? I haven’t found one, and the notoriously capricious approval process makes it unlikely a compelling app will get released quickly, and the notoriously clunky App Store makes it unlikely you’ll find out about it if it does.

Apple promises optimized versions of iWork, but even in landscape mode, the on-screen keyboard is no bigger than the one on the original 7-inch EeePC. And if you put the iPad in a comfortable position for typing, the shiny screen is at an awkward angle for viewing, especially in less-than-perfect lighting.

Am I rationalizing my recent purchase of a Lenovo S12 netbook, and wishing I’d saved my pennies for the iComeToJesusTablet? No. Not only didn’t I expect the iPad to ship before March, I never expect the 1.0 release of any Apple product to be stable, so I wouldn’t have bought one until at least June anyway, and in any case, I can afford to own both. Right now, though, I don’t want one, because I can only envision using it around the house, and all my stuff is already there, so why bother?

I get some use out of the iPod Touch, and I’ve often wished for a scaled-up version, but what I wanted scaled up was the capability as much as the size. The iPad has the size (very close to B5, with a bigger-than-B6 screen), but is basically limited to consuming content created on actual computers. So why not just carry a real computer when you want to work, and an iPod when you only need canned content?