No way! I download many books and read them on my tablet, because it is sometimes too difficult to find this book on the paper (old or on the other language). Also many books are too expensive for me: I read about 1-3 books every week, so I cannot spend so much money for it.
But I realy prefer to feel the paper, take it in my hands. So when I really like the book, I'll find it on the paper.
Yah of course , Hard books will never loose its significance as it is easy to read and access. Online books have its own drawback that it make person tired sooner than normal one, hurt eyes drastically and speed of reading is also slower than normal books.
Still online books are helpful in some cases when hard books are not available or you are unable to carry them with your self.
But these condition and cases will not help to reduce the significance of hard books.