Not much information is available yet for Old World Blues, the third add-on DLC for Fallout: New Vegas. The description, via press release, says that it takes place in "the trackless wastes of the 'Big Empty'... a no-man's land, a desolate stretch were no living thing can survive". Of course, players will find that this is just hogwash. We can also assume that this DLC will take place outside of the Mojave map.
Here are four screenshots to whet your good ol'-fashioned appetite (click to enlarge):