I know that many here would love Apple to bring something to the textbook market that would drive down prices for students but don't get your hopes up. Textbooks are the least competitive part of the book publishing business. Even though there are a number of publishers, each company holds a virtual monopoly in its area. That's why textbooks are ridiculously priced.
Any real innovation in the area of book publishing (and in newspapers and magazines, as well) will come where the competition is the most intense. Fiction is the best example: publishers hold monopolies on an individual book, maybe even an individual author, but not a whole category. A reader has choice. In textbooks there is no such thing as choice, if you need a particular book for your chemistry class you MUST get that book. The publisher will gouge you whether you want it in print or in e-book form. (That's why the big publishers love the mega-hit books, they are as close as they ever come to have a monopoly in the fiction category.)
That's why HarperCollins makes a good choice for Apple to work with. McGraw-Hill, Pearson, Wiley would not be as interested in new models. (Disclosure: I used to work for McGraw-Hill.)
What I want to see next week is not only a great tablet, but a demonstration of its use in e-publishing that is more than just a flip book, more than just fancy page turning. I would think Jobs could demonstrate an issue of a magazine like Wired that was specially designed for the tablet (there has been rumors that the Condé Nast magazine has been working with Apple since last fall). The demonstration would not only show the magazine like it appears in print, but also in a new layout (you can see several videos of magazine demos on my YouTube channel - the Bonnier one seems to capture the spirit of innovation the best), complete with embedded video and links, new content, the ability to link to and purchase advertised items right from the page, etc.