As a series staple, the Shadow Broker has played a background part to most of Mass Effect and Mass Effect 2. The mysterious information network even held Commander Shepard's body for a time after his death at the start of Mass Effect 2.
For whatever reason, representatives of the Shadow Broker have been merely side characters. Management types have been conspicuously absent. Upcoming DLC will rectify this, as Liara T'soni will be joining Commander Shepard and his team to confront this shady organization in The Lair of the Shadow Broker.
I have to admit, I'm a little behind on the ME2 DLC front. I have yet to purchase the Overlord DLC, but a second pack would certainly justify a 1600 point card dedicated to adding these experiences to my current Mass Effect 2 playthrough.