since the advent of the web reading has increased drastically and publishers are publishing more titles than ever. Merely looking at last year’s stats is poor reporting- last year the economy was in a deep recession and people weren’t buying. However, library use was up sharply.
I don’t believe there is a future for printed volumes. It makes no sense economically. However, I do believe there is a book-like format that will survive because all the media you describe do not deliver long format information, including stories, well. Books are an immersion experience, not a skimming experience.