I believe they will disappear as we know it...
It will not be in the next decades (specially because of the poorest countries), but it will happen sooner than later.
If you a take a look at the new interactive books on ipad, I think the future is that! it will create a new industry that will bring illustrations in books to a whole new level!
I think we're going to see worderful things appearing on the next few years!
But maybe the tablets or e-readers aren't the final "end" for the books, there's already experiences in "electronic paper" and a few other technologies.
Let's wait and see! I was a paper book lover myself but now, I'm getting more used to electronic ones! I tend to read one paper book and two electronic, to try to adapt! Specially because of space (i don't have a lot of space to store books) and notes (it's wonderful to take notes on ipad).