From a gamer forum:

Surprise announcement: About Twitter developer DICE has just announced that the multiplayer version of Battlefield: Bad Company 2 now available through the Xbox Live Marketplace for Xbox 360 ready for download. the size of the Scan version is 1.35 GB.I think it's safe to say that this will be one of the more anticipated demo's that will come out in the first quarter of 2010.

All you Xbox 360 users, get downloading!