Trophies are becoming quite the informant on upcoming downloadable content plans lately. Right on the heels of a Need for Speed: Most Wanted leak, Dishonored Trophies have appeared to let the cat out of the bag on a piece of content called "The Other Side of the Coin."
The list from PS3Trophies includes ten Trophies, some of which are no doubt spoilers for the story. Among the less plot-oriented trophies are one that rewards you for killing with an arc mine and a rat, and a few revolving around completing with High Chaos, Low Chaos, and without alerting any guards. It seems altogether more story focused than the previous Dunwall City Trials DLC.
Most likely this is the spring 2013 content. As previously reported, that content will feature the Whalers head Daud, complete with new weapons and powers. He'll have his own areas of Dunwall to explore as well, some of which are named in the Trophies list.
Shacknews has contacted Bethesda regarding the DLC, and will update as more information becomes available.