Well there are 2 DLC available,there both mission add-ons
http://marketplace.xbox.com/en-US/games/media/66acd000-77fe-1000-9115-d8024d5307e8/?of=3
there both also 400 ms points.
Incase your too lazy to click the link (i am most of the time) here they are
Pinnacle Station
"(Select this for the English-language version of this module.) Test the limits of your combat prowess aboard a remote, top-secret Alliance space station. Do you have what it takes to hold the top spot amongst the best of the best? This module includes a new land-able space station, 13 exciting combat scenarios, and approximately 2-3 hours of game play. Required: you must achieve Spectre status before embarking on this mission. There are no refunds for this item. For more information, see www.xbox.com/live/accounts."
Bring Down The Sky
"(Select this for the English-language version of this module.) Batarian extremists have hijacked a mobile asteroid station in the Asgard system, setting it on a collision course with the nearby colony world of Terra Nova. Only you can save the human hostages on the asteroid and reroute it before it crashes into the world, killing millions of innocent civilians. There are no refunds for this item. For more information, see www.xbox.com/live/accounts."