Amazon is promising textbook rentals on the Kindle that could save 80% over the cost of buying new. That is good news, and any competition to break up the cozy and price-inflated textbook market is welcome.
But Amazon is going to have to rethink the Kindle and its software before this is ever going to work. I am a huge fan of the Kindle (though I have switched my reading to the Kindle app on the iPad). But it works best reading a book straight through. Want to page back and find a particular section -- good luck. The iPad app actually works better, with a touch screen slider that allows a little better browsing. But for textbooks, they really need some kind of page navigation like coverflow in the iPod (which I hate by the way in the iPod but would love for pages in a textbook).