At a conference years back I was sitting on a panel that was asked to talk about future of the book. As the discussion was heating up about the inevitability of the electric media, someone on the panel (I wish it had been me) proposed a flip test. He said "Let's say the world has only e-books, then someone introduces this technology called 'paper.' It's cheap, portable, lasts essentially forever, and requires no batteries. You can't write over it once it's been written on, but you buy more very cheaply. Wouldn't that technology come to dominate the market?" It's fair to say that comment changed the direction of the panel.
It's a useful way to cut through the hype and actually think about how a new technology will actually be used. Go forth and apply it.
So what about e-books? The idea of a "book" as we think of it can't be separated from the physical object of the book. Long pieces of writing were printed, bound, and mass-produced because that was much cheaper and more effective than printing, binding, mass-producing, and distributing small individual chapters. The form of writing and the medium grew to fit each other.
I'm beginning to think that the very idea of an "e-book" is just a mental stop-gap. Kind of like the horseless carriage:
The first automobiles were literally carriages without horses. The design of a horse carriage - top heavy, open - wasn't suited at all to motor-driven transport, but that's the only way inventors knew to frame the problem. It wasn't until later they could take the next step and stop asking "How do I make a carriage move without a horse?" and start asking "How do I design an automobile?" A century later, no car designer thinks about horses.
So the question "Is an electronic book better than a paper book?" is the wrong question. There's an enormous amount of writing and reading going on on the Internet today, and almost no one thinks of it in terms of "books." I'm not sure what the right question is, but maybe it's something like "How do we get words from the people who write them to the people who want to read them?"