Speaking to Famitsu Weekly, Sony's head of Worldwide Studios Shuhei Yoshida confirmed that PS4 Share Play feature will be rolled out with the release of PlayStation 4 firmware 2.0.
Share Play allows friends to play their friends' PS4 games remotely without owning a separate copy. This is done through game streaming technology similar to the one used in PlayStation Now, so all progress and achievements will be stored on the game owner's account rather than the borrower's. Essentially, the system is designed to mimic visiting a friend over the internet.
Share Play requires no special support from game developers. Once firmware 2.0 is installed, the feature will be available for all games except the ones that use PlayStation Camera.
Each Share Play session will be limited to 60 minutes, but there is no limit on the number of sessions a friend can play a game.