In a discussion with Game Informer, Naughty Dog explained that PlayStation 3's exclusive title, The Last of Us, will allow players to play during the download if purchased digitally on the PlayStation Network.
To remove the delay for downloads when you purchase digital titles, once the download progress for The Last of Us reaches 50%, players can boot up the game and begin playing. Neil Druckmann – creative director at Naughty Dog- and Bruce Straley – The Last of Us game director – revealed that Sony worked on this feature for the release of their title.
This feature sounds very similar to the PS4's download and play capabilities made possible because of the PS4's hardware. At Sony's PS4 reveal, they explained that every PS4 will carry a secondary chip for background processing. This chip will allow players to almost immediately begin playing any digital title before completing the full download, compared to the 50% requirement for The Last of Us.
While you can begin playing after hitting the 50% mark, Naughty Dog did not specify if this includes both the single player mode and "best multiplayer ever conceived." Many games, both on the Xbox 360 and PS3, pause any downloads when you begin playing games online.
The Last of Us will hit store shelves and PSN on June 14th for the PS3.
Source: Game Informer