Beware: Only the disc version still offers co-op functionality since the DLCs and the necessary patches are included on it. The PSN has been disabled as of 09/03/2019.
Two players can play through special co-op story missions in split-screen (horizontal).
The Game of the Year Edition contains both the game as well as all the DLC released for it:
This page contains co-op info for Uncharted 3: Drake's Deception - Game of the Year Edition on the Playstation 3. All information about Uncharted 3: Drake's Deception - Game of the Year Edition was correct at the time of posting. Information is subject to change. If you see any errors please email us.