I love Frank Chimero’s explanation of the book design decisions he made for The Shape of Design. From an interview with FontFont:

Many of the design decisions were also influenced by the affordances of ebooks and their readers. The cover was designed to be very iconic so I had a design system which could transition to each reading environment. The page size of the printed book was chosen to be similar in size to what would be experienced on an iPad or Kindle. The illustrations are two-color, because I knew I could make them look good on a Kindle, iPad, and in print.

Basically, I wanted to design a system that was flexible enough to keep its identity intact as the words went from place to place. I think it is possible to craft books in a way so that no reading environment is obviously inferior to another, whether printed book or ebook. Each piece has to shine on all the other parts to make a better whole.