Even when we get to the point where we have cheap e-paper that can be folded like normal paper and requires no power?
Yes. I'm inclined to suggest that the majority of people on the planet, don't actually have access to the internet. But I don't know for sure.
If we ignore all those people who (while may have the skill), are largely illiterate, I would still suggest that currently, a huge proportion of those people probably don't have any easy access to the internet at all.
Try supporting a completely non-technical user base and you'll see how adverse most people are to accepting computer technology no matter what form it is presented in. And until you kill off all those people who don't do computers, paper will be their preferred medium.
Plus normal books rock, I'm a proper computer geek and I'd much rather read a book than mess about with some ereader bollocks.