Today at the Techonomy conference in Lake Tahoe, CA, CNBC’s Maria Bartiromo sat down with a panel including Bill Joy, Kevin Kelly, Nicholas Negroponte, and Willie Smits. The topic was basically the future of technology. And Negroponte had the most interesting (or at least the most controversial) thing to say.

The physical book is dead, according to Negroponte. He said he realizes that’s going to be hard for a lot of people to accept. But you just have to think about film and music. In the 1980s, the writing was on the wall that physical film was going to die, even though companies like Kodak were in denial. He then asked people to think about their youth with music. It was all physical then. Now everything has changed.

By “dead,” he of course doesn’t mean completely dead. But he means that digital books are going to replace physical books as the dominant form. His argument is related to his One Laptop per Child Foundation. On those laptops, he can include hundreds or thousands of books. If you think about trying to ship that many physical books to the emerging world for each child, it would be impossible, he reasons.

“People will say ‘no, no, no’ — of course you like your libraries,” Negroponte said. But he cited the report that sales of books for the Kindle recently surpassed sales of hardcover books.

“It’s happening. It not happening in 10 years. It’s happening in 5 years,” he said.

Naturally, I love these type of predictions.

