'Onslaught' mode pits up to four players "against an onslaught of enemy AI" to complete objectives on the multiplayer maps Atacama Desert, Isla Inocentes, Valparaiso, Nelson Bay, redesigned with "new lighting, time of day, added vehicles and other effects."
As to why DICE has not confirmed a PC version, associate producer Barrie Tingle offers the following explanation on the Bad Company 2 PC forum.
The problem we have on PC is that all our servers are dedicated with providers. Changing a server from Conquest 32 players to Onslaught 4 players cuts out 28 player slots from the total ammount available. This could have a dramatic affect on the PC online environment if enough servers changed to Onslaught.
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.
Neither a release date nor pricing details are known for the Xbox 360 and PlayStation 3 editions of Onslaught mode, though Tingle's explanation suggests that it is paid downloadable content. A flashy teaser trailer for Onslaught follows below.
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