From Tom Shelton on Twitter to a fresh article in the New York Times, I've been seeing new probing about why paper textbooks are not rapidly being replaced with on-line versions.
My hunch is that full replacement will never happen. The special genius of books isn't in the individual pages: any given page can be shown just about as well on a screen. The special genius of books, and magazines, and catalogues, is in how the pages relate. It's in the way a reader can skim quickly to find an item of interest and flip back and forth to see how the different parts relate. That's why I can see an EdWeek headline in three different e-mails and two different Google Reader links, and only become intrigued by the story when the paper copy lands on my dining room table.
For that reason, I think students will always need books, actual books to organize the main big picture of each subject they study. Most teachers will also value that firm organizer of the main content for a given course of study.
The key thing is that the books no longer need to stand alone, and they no longer need to be loaded down with other kinds of learning resources that can be offered better electronically.
I predict a future that uses the strengths of both.
The standard book for a course can be much shorter, designed to convey the key concepts and connections quickly.
Then, as students work their way through the book, they can use digital tools to dig into how those ideas each work. We're already seeing software that lets students work math problems that adjust in difficulty to provide more practice where needed and more challenge where appropriate. Think about how much clearer Newtonian physics and animal anatomy can become with interactive videos. Imagine being able to switch at will from maps of individual battles to the full global view of World War II.
Those options can be easily indexed to the chapters of a textbook, or even to the somewhat different approaches of multiple textbooks. They can be official parts of a given class, or items students find and use for their own added study. Students studying the same chapter, with the same teacher, can use different supporting tools to build their understandings. There can even be room for discussion about the textbooks themselves, so that students can consider arguments about whether any given book gives too much or too little weight to some aspects of a subject.
That hybrid approach, with the textbook still essential but smaller in scale and price, and digital resources important but still related to a core printed structure, looks to me like the the most probable future.