You cite only non-fiction reference material in your examples. I'd say that the book has more staying power in fiction. There's just something nice about reading a book to relax, curled up on your couch by the fireplace. That's different from opening a book to learn/check something you need for work.

The kindle and ipad do well enough to replace physical books for curling up by the fireplace, but the abstract concept of the book seems safe to me, for fictional pieces at least. Of course, none of us can really know until we get to the future. :)