How big? According to Eurogamer, big enough to require an eight-person writing team which will include lead writer Mac Walters. The untitled DLC is being developed by BioWare's Edmonton studio, and according to one of the company's designers, that number represents pretty much the entire writing team there.
But BioWare's not just throwing a bunch of writers at the next story set (presumably) in and around "Mass Effect 3."
Seth Green is making his "Mass Effect 3" DLC debut in a return to his role as Normandy pilot/resident joker, Joker. Also returning is "Mass Effect 3" composer Sam Hulick, whose work can also be found in "Baldur's Gate" and "Red Orchestra 2: Heroes of Stalingrad" as well as "Mass Effect 2."
So what will the next piece of DLC entail? It's anyone's guess, but each one has dealt with the same problem of getting their hooks into a player who may or may not have already finished the main story, making the stakes feel a little less urgent. While the excellent "From Ashes" added a new crewman to the Normandy, subsequent installments have really explored backstory in curious ways or attempted to up your readiness for the final, likely already-completed final battle.