This from Games.on.net.....
Battlefield: Bad Company 2 shifts 5 million units, celebrates with new co-op mode
By Brenna Hillier - Thu May 13, 2010 4:03am
Battlefield: Bad Company 2 is a bit of alright, isn't it? Five million happy consumers apparently think so! You couldn't blame DICE for resting on their laurels, but instead, they're beavering away at introducing a new co-op mode: Onslaught.
It's not yet clear whether Onslaught will be a free update or a piece of premium DLC, nor has any release date materialised. What we do know is how it works: you and three mates against the onlsaught of AI enemies.
Four maps - Valparaiso, Atacama Desert, Isla Inocentes and Nelson Bay - have been redesigned especially for the additional mode, with new lighting, vehicles, and even differing time of day. Each of the four will have a distinct combat focus, but require attentive co-operative play.
The announcement has caused a bit of controversy because it's only been confirmed for PlayStation 3 and Xbox 360. But... but what about PC gamers? Don't worry, folks; it's nothing personal. Technical difficulties are at the heart of the delay, a DICE spokesperson explained on the game's official forums:
"No, we haven't signed away rights to console on this. The problem we have on PC is that all our servers are dedicated with providers. ... We aren't ruling out Onslaught on PC but at this time we are researching how to bring it to PC without affecting players who don't have Onslaught or their own server to run it on."