In my opinion, E-books will spread more and more in many ways. Especially it will be used for study. We can easily recongnize it wil soon become ,or already becoming huge economy market.
For me, it is mixed blessing. Main reason is that it is hard for me to look at screen for long time. Last year, I took TOEFL. I used paper-based textbook for preparation. The real exam was iBT, which stands for internet based test, and it was pretty difficult to focus on reading the text.
It is also hard for me to learn new words or stuff without writing it down on the paper.
For this reason I am paper-based person. I guess I will not use it that much in the future.