There are many reasons I'm wary of Apple's potential tablet, but the thing that makes me most anxious -- the corner I can't see around -- is the input mode. In short, how is the user going to get information into the tablet? The answer to this question will go a long way towards answering the larger "What is it good for" question about the tablet; I see little point to the rumored tablet version of the iWork suite if there's no easy way to author documents.
But will be that easy way? Macworld's Dan Moren tries to come up with the various possibilities, none of which seem to be exactly perfect. He even posits a "no text entry" option, which seems pretty insane -- after all, even the iPhone has text entry, and people are visualizing the tablet as being more than the iPhone.
It's wholly possible that the tablet will just completely lack something that we will all assume is vital to it. This is a not atypical Apple move: think, for instance, about the original iMac, which stunned the world by not including a floppy disk drive of any sort. But it's hard to imagine no text entry functionality for a tablet, or very rudimentary functionality. If nothing else, you need to be able to fill out Web forms and enter passwords.
John Gruber has an interesting essay on the Newton, which he calls "the original tablet." While we may think of the Newton as a precursor to PDAs and smartphones, it was really quite large -- more the size of the proposed tablet. Of course, it had a famously wonky input system, but Gruber argues that its problems in this arena were overstated, and its real failure resulted from simply not offering enough functionality for its substantial pricetag. Fair enough! But interacting with the tablet is going to be the functionality. That's the secret of the iPhone's success: other phones may have the same features, but their easier and more fun to use on the iPhone. The tablet has to be really easy to use from the get go -- and that means Apple will have had to solve the input problem in a clever way. Apple's good at solving problems, no doubt; nothing's leaked out about how they solved this one, though, which means that either everything that has emerged is a controlled leak and this is the secret weapon they're waiting for January 27th to wow us with, or that there's nothing to tell.