The PC PowerPlay Website has a preview of the next print issue of this Australian gaming magazine, which offers a confirmation of various indications that multiplayer support will be included in Mass Effect 3, BioWare's upcoming action/RPG sequel (thanks Joystiq). They show the magazine cover which mentions the multiplayer reveal, and offer the following description:

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.