For the non-fiction author therein lie possibilities to create the proverbial last word on a subject, a one-stop shop for all the information surrounding a particular subject matter. Imagine a biography of Wiley Post, the one-eyed pilot from the 1930s who was the first to fly around the world. It would not only offer the entire text of a book but newsreel footage from his era, coverage of his most famous flights, radio interviews, schematics of his plane, interactive maps of his journeys, interviews with aviation historians and pilots of today, a virtual tour of his cockpit and description of every gauge and dial, short profiles of other flyers of his time, photos, hyperlinked endnotes and index, links to other resources on the subject. Social media could be woven into the fabric of the experience--discussion threads and wikis where readers share information, photos, video, and add their own content to Post's story, which would tie them more closely to the book. There's also the potential for additional revenue streams: You could buy MP3s of popular songs from the 1930s, clothes that were the hot thing back then, model airplanes, other printed books, DVDs, journals, and memorabilia.
A visionary author could push the boundaries and re-imagine these books in wholly new ways. A novelist could create whole new realities, a pastiche of video and audio and words and images that could rain down on the user, offering metaphors for artistic expressions. Or they could warp into videogame-like worlds where readers become characters and through the expression of their own free will alter the story to fit. They could come with music soundtracks or be directed or produced by renowned documentarians. They could be collaborations or one-woman projects.