In many cases, books are related to events. Novels, stories, business accounts, history, … and many other fields are based on relating and presenting a sequence of related events. In many of these cases, these events are captured by an author and are presented in the way (s)he considers it best. Using text, these descriptions become abstract. When people feel need to provide more details, they resort to experiential mechanisms like photos and video. Of course, books could not include video so video and movies eveolved parallel to books. Books were converted to movies and movies appeared in form of books. And there is much debate whether a book is better or is the movie better. We will not get into that discussion here — but the important fact is books try to create experinces relying on abstract descriptions and the imagination od the reader. Movies and videos try to be very explicit in presenting experiences — movies are recreating experiences and much of the video is capturing experiences.
Knowledge captured in books is usually the result of experiences and insights gained from such experiences by people. Technology now allows caputre of at least audio and visual experiences of humans using sensors. These experiences have already revolutionized the way people interact and communicate. Recent popularity of video, not only on YouTube, demonstrates human desire to share experiences in their sensory form. Evolving books should allow this.
A major physical limitation of the book was that it had to be finished to start sharing with others. Finishing did not necessarily mean that the authors thought that they have said everything that they wanted to say — it only meant that at that point in time (due to several external factors) they had to committ to what could be put in the book. And then the book was frozen. It could come in the next edition again at fixed time. This limitation has suddenly become much less important. Now I could start sharing a book, or a paper, well before I think it is really finished. I may just feel that it is in a reasonable shape to share with people. Good thing is that by sharing it I start getting feedback and can use that to revise it to prepare the next version. There is no pressure, like in good old days, to finish it in a form that can not be easily changed. Now I can have a book available in a form that I can modify, if needed, every day — or every hour, or every time I feel like doing it. So the book acquires ‘life’. It is now something that lives and changes with new experiences of the author. Or maybe multiple authors. Not only that, it could also use not only abstract knowledge but also experienctial knowledge. So a book now becomes a multimedia document that uses different media as appropriate to share thoughts, logic, and experiences of authors. And it represents the state at any particular time. Of course, one could save the state on any particular day, but that does not gurantee that things will not keep changing in the book. Like just because you take the photograph of your child does not mean that the child is frozen in time and will stop growing.
While assembling books, network starts playing a very important role. You assemble things from different places by linking to them. I am sure you have experience of putting photos on Flickr, thoughts on your blog, videos on YouTube and linking all these to create a full picture, so to say, of the situation. You want to link to different things. And this network of documents becomes the book. One could take it to extreme and consider in a trivial sense the whole WWW to represent a book. Or one could define only a relevant set of such linked documents of different media types to be the book.