According to a recent post on the official BioWare forums, it's going to be a VERY happy new year for Mass Effect fans.
This demo will have both single player and multiplayer sections, with the single player portion being available from day one. Redemption of the Online Pass for Battlefield 3 will give you early access to the multiplayer demo.
Additional ways to gain early access to the multiplayer demo will be revealed in November and December.
The Mass Effect 3 demo will launch sometimte in January (the exact date is yet to be announced).
About Mass Effect 3
Earth is burning. Striking from beyond known space, a race of terrifying machines have begun their destruction of the human race. As Commander Shepard, an Alliance Marine, your only hope for saving mankind is to rally the civilizations of the galaxy and launch one final mission to take back the Earth.
Release Date: March 6, 2012
ESRB Rating: Rating Pending
Platforms: Xbox 360, PS3, PC
Buy Mass Effect 3