The technology also isn't quite as good as a paperback yet. There's still eye strain, the difficulty of making legible notes (styluses are getting better and better but they aren't quite the same as pen on paper yet), battery life, availability of rare titles, and so on... I like having a large collection of paperback books and the feel of one in my hand, but I also recognize that in the next 10 to 20 years ebook technology is going to make such advances that it'll almost certainly replace a lot of my library. When they have a device with 48+ hours of battery life, a natural-looking screen that doesn't cause extra eye strain, the ability to easily take and save legible notes, OCR and text search, every book available in digital format, and the ability to easily cross-reference a thousand other titles....that sounds like a dream to me as an academic. We're not quite there yet, but it's going to happen sooner rather than later.