The popularity of e-books will increase with the adoption of smart phones or such devices. Today I am reading electronic versions of books that are not easily available or are out of print. Tomorrow I might be reading more contemporary books in their electronic form because they might be cheaper and more convenient to read (or consume in audio form) that way.
In Singapore, I already see young people reading books (or longer texts) on their phones on the bus. Singapore National Library has a website where people can submit their short stories or download a short story to be read on their PDAs or phones. In Japan, people are reading novels on their cell phones. Elsewhere, people are tweeting their novels. In the next two generations, e-books might become the mainstream reality.