In an interview with Videogamer, Mass Effect lead producer Casey Hudson said a "continued stream" of DLC packs are now being developed. And rather than creating simple one-off adventures, the DLC will be constructed to tell the tale that leads up to the epic adventure in Mass Effect 3.
"So, for the time being there's going to be a continued stream of DLC for people," Hudson told VideoGamer. "We'll start to have packs that'll tell the story between Mass Effect 2 and 3. But beyond that we kind of have to see how people are responding to what we have and go from there."

No word on whether or not Overlord, the upcoming DLC pack set to drop on June 30, is part of the Mass Effect 2.5 story arc.
Hudson also confirmed that BioWare is already hard at work on the third installment in the Mass Effect trilogy, but said it would be "quite a few months" before the developer is ready to provide any details about the game.

