When it comes to DLC's, I think they should make more than just the the next two if thats all they are planning on, honestly in my opinion, I think that Fallout: New Vegas has ALOT of DLC potential, take a look at the map on your Pip-Boy, then look at all of the unused space around the Mojave Wasteland, I think they could add so many more locations. And does anyone know of what all of the pre-existing locations in Fallout New Vegas are the DLC gates, I know the first two, The Abandoned BoS Bunker, and The Nothern Passage, does anyone have any idea what the ones for Old World Blues and The Lonesome Road might be?
For Old World Blues, I'm guessing it is the unmarked train tunnel in the southern portion of the map. The preview shows a crashed sattelite next to the drive-in there, so that's probably why it's not marked because the DLC actually starts there but you leave and return from the train tunnel.
For Lonesome Road, it is likely the Canyon Wreckage near Primm, as the Divide is supposed to be near (or possibly is part of) Death Valley, which is directly west of that marker. Also, it has graffiti about you, one saying "Lonesome Road".