User blog comment:Commdor/Omega DLC Plot Elements Leaked/@comment-3228423-20120925163630

Maybe the Omega DLC was supposed to take place before the Volus Ambassador mission and the events on this mission would make him turn on Cerberus during the latter mission.

Or if the Volus Ambassador mission were to be completed first, Zaeed could be there just to f*ck up Cerberus' plans.