This blog entry from Tim O'Reilly is worth reading. Here's the money quote:
As authors and publishers explore the new world of ebooks, we need to do more than just translate print books to an electronic screen. We have a future to invent! And the time is now.
Put me in mind of my (too long) series on the Age of E-Quarius, although O'Reilly is definitely more of a high-brow brainiac than I am.