The first expansion pack for Battlefield: Bad Company 2 will be released only as a DLC. (Cue people complaining about DLC.) EA says Battlefield: Bad Company 2 Vietnam, which is scheduled to be released this winter, will only be available via download.
What’s in the DLC? Four new multi-player maps, a bunch of new era-specific weapons, and the song “Fortunate Son” by Creedence Clearwater Revival. There will be 49 new songs, again, all from the era.
And yes: Call of Duty: Black Ops takes places in the same era.