XBL Radio writes: "Now available on the Xbox Live Marketplace for 800 MP is the "Operation Anchorage" DLC for Fallout 3, which takes you through a simulation of the liberation of Alaska from the Chinese. I don't want to ruin anything for anyone - so I'm going to keep this as detail free as can be.
Don't expect any new blip location on the map when you load up your Save file, after the DLC download. That's not how you activate the new content. Actually, you receive a new radio transmission on your Pip Boy from some "Outkast" looking for help in the form of fire power. I didn't receive the transmission at load up either; it took a minute or two. Wait for it."