The current surface forms for digital books are far from perfect, but they work and are getting better with each device and software iteration. So, in my opinion, many of the critical future questions digital books designers will have to address don’t directly involve pure content layout. Future-book design is not merely about font sizes and leading. Instead, our hardest (and possibly most rewarding) problems will involve the intermingling of content and data.
Craig Mod — The shape of our future book.