Sony’s games won’t include DRM restricting the sharing or reselling of used games. Basically games for the PS4 will work just like before.
Sony even included an easy instructional video regarding their game lending policy, for consumers who wish to share games with friends.
Sony went out of the way to point out in their E3 press conference that games on Playstation 4 belong to the customer, and that they are free to do what they please with the games they purchase. They don’t require online verification to play, the game is yours to sell or lend to friends. Sony emphasized you can play your games offline for as long as you like and that the PS4 wont shut down if don’t check in every 24 hours ( an obvious jab at Microsoft’s DRM policy).