Ebooks are continuing their blitzgrieg assault on print publishing. Book publishing is starting to go through similar convulsions to the recording industry. Unlike the recording industry, piracy is not a massive issue (yet). But Ebooks are not just replacements for the printed book. They are something very different, and will become more different still. If the ebook does largely replace the printed version, designers, publishers and authors will have to make many adjustments. Ebook readers may expect a much more sophisticated and dynamic interface than a print book could ever supply. Their expectations of what constitutes a 'book' will rapidly alter. Content will shift to match these expectations. And unlike the printed book, which took essentially the same form for several hundred years, the ebook will be subject to continued and rapid development.