I really can't see a Netflix-type system, though. Unlike movies, there has never really been a successful rental model for books, and I don't see that changing.
Similarly, I don't see a rhapsody or e-music type subscription model working because I don't see how the authors/publishers can make any money from it - it would basically just cannibalize sales.
Of course , before a successful movie rental model was established, there wasn't a movie rental business. We just don't have the right model right. We know people are willing to borrow books for a while: there's no reason in principle why they wouldn't borrow books for a fee if they could borrow any book they liked, anytime they liked, rather than just the collection available at their local library