Australian Magazine PC Powerplay have revealed that Mass Effect 3 will indeed be getting a multiplayer mode.
"That's right - Mass Effect 3 is getting multiplayer! We travel to BioWare's office in Edmonton for hands-on time with the series' first foray into online gameplay, and chat with Mass Effect Series Producer and Mass Effect 3 Project Director Casey Hudson about the decision to go multiplayer in the epic battle for the galaxy."
No details have been announced on the multiplayer modes, but rumours have it that it will feature co-op play. Some text on the magazines November front cover reads: "Fight alongside your friends as the galaxy goes to war!", which would confirm co-op play.