The Call of duty 4 page on Xbox.com revealed that the new Variety Map Pack will be released April 3rd for 800 MS points. The map pack will include four new maps Chinatown, Killhouse, Creek and Broadcast.

Map Details:
The Variety Map Pack includes four new multiplayer maps. "Creek" is a wide-open village ravaged by combat where concealment is the difference between life and death. In "Broadcast," fight throughout an enemy communications building with confined corridors and wide-open parking lots. "Chinatown" is a foggy downtown district, lit only by a full moon and the neon glow of the city. "Killhouse" features a desolate training warehouse filled with a variety of building mock-ups and soft and hard cover points.