The latest DLC for "Sleeping Dogs" called "Year of the Snake" is currently available. This story-driven DLC takes place after the events of the main story. This DLC pits Wei Shen against a doomsday cult.
The latest DLC has been released for "Sleeping Dogs" which brings a story of it's own. It is called "Zodiac Tournament" which is a homage to the old Kung-Fu movies such as Bruce Lee's "Enter the Dragon."