the $1 Billion dollar worldwide sales mark? You announce some DLC to keep that game going strong. Activision announced today its first DLC map pack for Call of Duty: Black Ops entitled First Strike. The new DLC Map pack is slated for February 1, 2011 to be released on XBox Live.

“We’re committed to supporting Call of Duty: Black Ops fans with continuous updates to the game and exciting new content that will keep our community engaged,” said Treyarch Studio Head, Mark Lamia.

The map pack will include four new maps:

• Kowloon - Kowloon city in china, except this time on rooftops
• Berlin Wall - Located in Berlin at the infamous Checkpoint Charlie
• Discovery - an Antarctic research station
• Stadium - takes place at a hockey rink in the US

A new Zombie map called "Ascension" will also be included in the map pack, but no details on that one yet. The new DLC will be a timed XBox exclusive. Meaning, if you're playing it on any other format other than XBox Live, you're going to have to wait at least a month until you can get your hands on it. Also, if you are an XBox Live Silver member and have not had the chance to get in on the multiplayer action, XBox Live will be hosting a multiplayer unlock event from January 28 - 30^th to make you all convert to full memberships.

First Strike will be available for 1200 Microsoft points ($15). Activision also announced today that Call of Duty: Black Ops passed the $1 Billion mark in worldwide sales, so congrats to them. Keep an eye out on the website for First Strike updates in the coming months.