What is the future of books in general given all the info here on-line?

I corresponded with a well known author about the 4th edition of a nonfiction book he wrote. He said there probably wouldn't be a 5th ed. because there is so much very current information on line that a book on the subject is no longer necessary. I was saddened and shocked. What is the future of non-fiction books when you can get a great deal of information that is even more current on line? Should I take down my book shelf and replace it with a CD holder?