I'm not very sentimental about books, unlike other commentors in this thread. I don't really care about the smell, the feel of the pages, etc. To me the book is the same however I'm reading it, and I have to say my Kindle is incredibly convenient, and has made my bus journeys a hundred times more enjoyable. Despite this, I don't think e-readers spell the end of print books. There's a difference between magazines like Newsweek and books. Magazines and newspapers are quickly consumed, and easily discarded, so of course people are going to prefer an easier way to consume and discard them. Books take some time to consume, and for the moment it's still cheaper to buy a paperback and carry it with you than to buy a kindle and a paperback. Additionally, the issue of convenience comes up. Sure, a Kindle can put your entire library in your pocket, but it also runs out of batteries. You can't take notes (easily/quickly) on a Kindle - my copy of Catch-22 is covered with scribbles in margins. I don't understand why it has to be a battle between the digital and physical. People are always pooh-poohing newfangled technology that defeats the essence of books, or old fashioned ideas that are inefficient and outdated. Both mediums have their uses, and I don't see print going out of use anytime soon.
Indeed, books themselves were a radical innovation and departure from scrolls. The binding was a major technological breakthrough that allowed massively larger amounts of information to be stored and referenced much more easily. Because scrolls had to be spread out and rolled up as you moved back and forth through them, info retrieval was laborious, and texts were often broken down into collections of scrolls for brevity to mitigate this. Once that happens, things like losing them gets easier. Books pretty much brought as much content as you wished in one unit, with the ability to access any portion of the content with comparatively lightning speed. Ereaders are just another innovation in a long line of innovations for consuming the written word. I find they offer several advantages over paper, as well as some disadvantages of course. But I find I'm reading more now than ever because of them, and have access to worlds of context that I didn't before when reading various volumes.