Microsoft recently released their latest Games On Demand and Battlefield: Bad Company hit the line-up for $19.99 USD, that includes Conquest Gamemode and 8 bonus maps (separate download).
Also, we still have Multiplayer game servers running making this a perfect way to extend your online Battlefield experience from Battlefield 1943 or to get some early training for Battlefield: Bad Company 2 coming out March 2nd, 2010.