Looks like they're adding in a lot. New ways to play, new gun, new interaction, now this is a DLC!!!
http://news.filefront.com/holy-crap-shadow-broker-mass-effect-2-dlc-trailer-wow/Totally worth the money. I like DLC's added to the game, we're getting professional mods, even though they're not free, they're still very fun and i can't wait for this one.
Liara T'Soni is tracking down the mysterious Shadow Broker, and no one is safe. She'll do anything to recover the man the Broker kidnapped... and the Shadow Broker's agents will do anything to stop her. Team up with Liara and chase clues from the luxurious heights of Illium to the Shadow Broker's own secret lair. Adds the Shadow Broker intel center, new research, and five new achievements – and the chance to continue a relationship with Liara.
http://masseffect.bioware.com/info/dlc/