I tend to be pretty skeptical about these sorts of prophecies--parallels to iTunes and its impact on music sales do not seem to follow. For one thing, there is a different aesthetic when it comes to listening to music compared to reading a book. Music is not tactile (unless you are playing it); as a result, the delivery system for music is indifferent: whether it is a LP, 8-track, cassette, CD, or MP3, it doesn't matter as long as the audio experience is the same (or improved).
But reading has its own experience--from opening a brand new book to sniffing it (I love the smell of Eerdmans books!) to paging through it and sampling the pages. These are things that will never be duplicated or recreated in a digital form.
Likewise, the whole phenomenon of old books cannot be duplicated either--there is something about antiquarian books that moves us, I think. The care to preserve this title; the associations for the generations that maintained it and passed it on; the serendipity of finding a particular old book; the necessity of libraries (still in our digital age); the hopes of portability--all of these things cannot happen with the Kindle.
I admit that I'm a hopeless bibliophile and former archivist--I have a very healthy respect for the book, which predated Gutenberg. The form has lasted at least five thousand years--not just the idea of writing words, but writing them on paper to be preserved and shared. Far after this weblog or some e-book's pixels have disappeared, I suspect that Augustine's On Christian Doctrine will still be around, printed and bound, waiting for a rediscovery.