What's going to change books the way iPods have changed music?
Electronic Paper. I don't mean the kind of rubbish we see today from Sony, the iRex iLiad or even the Amazon Kindle. I mean sheets of paper, that require no power, where you turn the pages with your hands. Like real paper, but you can replace the content.
Xerox Parc were working on it, along with 3M, but closed it down in 2005 and have been seeking partners to license the technology. Philips were working on on it too, and early this year spun a company off from its research labs - Polymer Vision. Readius is their shiny little display, but how long before they produce a USB compatible book?
The book format matters because it doesn't need power. If you only have a single sheet you need memory and power to update the screen. If you replace the screen with pages then you supply the power and each page is its own memory - it's a very clever form factor that old book.