Puhleeze. This is the ultimate in pretension. Everyone knows the bookshelf is there not to hold the books after being read but instead the ones that have yet to be read. Books that have been read are shipped off to a used bookstore. At least for most people.
When people visit me or The Girl they are always amazed by the collection (size and content) on the bookshelf. Interestingly enough I have read many of them, but even a prodigious reader like myself has many books displayed that have yet to be read. In fact, I would contend that the avid reader actually more bookshelf on unread than read books.
Anywho, all this is to say that the digital age will not replace the book. Even if (some) people did not find reading a book preferable to the digital version, the image of the book contains a social currency that cannot be captured by a digital device. Similar to the framed degree displayed on the wall.