From a standing start in 1984 compact discs overtook phonograph records in 5 years. Paper books will put up more of a fight because of inertia and because it will take time for adequate display technology to reach many people. But it is inevitable.
In 7 years some bookstores will become half compact disc stores, thereby quadrupling the number of titles per meter of shelf space, but otherwise keeping many of the ills of paper publishing since retailers will still have to order as many copies of each title as they think they can sell.
This will take 7 years or more to allow for the time needed to scan most of the books that exist only on paper and to allow for cultural inertia and technophobia; some people will dislike the idea of electronic books. But once a book exists in at least one electronic form, it is easy to print it if necessary, convert it to another electronic form, or distribute it electronically. Electronic books contain paper books as a special case.