That map pack has a "planned release [of] Spring 2010," going by the specially marked "Monster Assault Energy" four-pack that just arrived here at Shacknews.

Whether the referenced map pack is the first downloadable add-on for the anticipated November 10-due shooter remains to be seen--developer Infinity Ward has promised "at least" two maps packs, both of which will hit Xbox 360 before PC and PlayStation 3.