While we have become a technology age where everything seems to be going electronic I feel there will always be libraries in the future which will contain books. While some individuals like reading books on a screen many others like the paperback or hardback variety.
Reading books on a screen is great to some extent but I myself like paperback or hardback books. This does not mean there will not be changes in what libraries will have. In the future which is already here libraries have both electronic versions of books and the paperback/hardback varieties. There is room for both in the future of libraries as we will know it.
I have purchased electronic books and I am satisfied with them but it is dependent upon the content. There are a great many books which have an electronic version and a paperback/hardback version. Today we as authors must provide books in any format that will reach interested readers. It is all about providing what we sell in the format buyers want.