User blog comment:Arbington/BioWare will be at Comic Con, and so will new Mass Effect info./@comment-71.92.122.146-20120709220213/@comment-899316-20120711022650

The playable MP DLC is going to be Mass Effect 3: Earth. Given the datamining leak and voice actor confirmation, we can safely assume that the SP DLC will be the Leviathan DLC.