If you think of it, ebooks are fundamentally the same as printed books— words on e-paper are not that different from words on dead-tree paper. Once we have good color e-ink and large screen eReaders that don't cost an arm and a leg, even graphic novels could go digital.
An ebook is, in fact closer to what the author wrought, in many cases, because today most books are written on computers rather than on a typewriter or longhand. An ebook novel does everything a printed novel does— sucks the reader into a world of the author's creating. If it's spec fic, that could literally be a different planet, but even the most mainstream novel is set in a world that is someone's creation, in terms of the characters and what happens to them.
But what about taking it one step further? Since technology allows books without paper, do novels have to be confined to just words, and sometimes pictures? Anthony Zuiker, creator of the TV show CSI, recently annouced he has created a multi-media "digi-novel" called Level 26. As readers progress through the story, they will be prompted to log on to a website (logon code provided in the book) to watch a brief film tied to the story. Zuiker calls is a cyber-bridge.
Readers will also be able to contribute their comments to the story. Zuiker describes his efforts as bringing a new level of technology to book publishing. My questions would be, first, do we need it? I, personally don't want to stop reading if I like a story. Level 26 can be read in print or on a Kindle, but even on a Kindle you have to log on to the web on a different device to view the video; reading the Kindle version on an iPhone or iTouch would be the most seamless experience at present, but platform aside, I don't want to stop reading!
And second, at that point, can you really call it a novel?