BioWare have announced that the next DLC pack for Mass Effect 2 will be called The Lair of the Shadow Broker. It will see the return of Liara T'Soni, a core character from the original Mass Effect.
Liara briefly makes an appearance in Mass Effect 2 and at that time, players learn that she's hot on the tail of the mysterious Shadow Broker. This DLC will allow you to enter the Shadow Broker's lair, and also to improve your relationship with Liara.
It will cost 800 MS/BioWare Points and is due out on the 7th of September on Xbox 360 and PC.