EA will bring tidings of joy in January 2012 to Battlefield 3 owners that have redeemed their Online Pass, by granting early access to the multiplayer portion of the Mass Effect 3 demo. The demo will include both single player and multiplayer sections, the exact launch date and the length of the early access has yet to be determined.
There won’t be any extra codes needed, just your Online Pass from whichever platform you are playing BF3 online with. If you won’t be adding BF3 to your game collection, there will be another program in which players and fans of Mass Effect will be able to unlock the early access. The launch date of the program will be announced in late November or early December. There will also be a tool on www.masseffect.com, which will allow players to check if they have been granted early access.
[Source: Mass Effect 2 Facebook Page]