"At a roundtable this morning, Sony's game studios chief, Shuhei Yoshida, told reporters that any requirement for users to register a game online in order to play it would be left to game publishers. Sony won't require that."

This has already been posted that PS4 DRM will be left to the publishers, much like online passes are now. Any publisher that adds a used game pass to their title, the title is going to bomb. Guaranteed. We'll have to see what publishers, if any, have the balls to actually go through with a used game pass, but for now, I'm going to think none do and take it that PS4 has the same DRM that PS3 has. Online passes only.