Some of you guysmay have already discussed this but here is a theory of mine on how the DLC honest hearts are going to commence.

As some of you may remember in Fallout 3 The Pitt you had to enter the train tunnel first before you could travel to pittspurg or the pitt. I believe that this aspect is used againin the upcoming DLC's.
First off it has been hinted that MT. Zion is in the DLC honest hearts. Mt.Zion is located directly east of Nevada in at the bottom of Utah, or near the location Canyon Wreckage where there is graffiti telling the courier to go home.
Coincidence I think not as the grafiti also refers to courier 6 who Johnson nash mentions in Primm.

Whether this location has to do with the the courier who cancelled the job to deliver the platinum chip (also known as courier 6) or if it has to do with Mt. Zion national park I do not know, but I have a feeling that the Canyon Wreckage is involved in an upcoming DLC.

or it could be the area up north from Brooks Tumbleweed Patch which has the burned man graphiti.
http://images.wikia.com/fallout/images/4/42/Honesthearts_display.png

On a different topic at the very north of the fallout new vegas map there is a location called northern passage which is corrently caved in and has no current purpose. this could mean that it might be part of a future DLC

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
All those above are the 3 known locations for dlc starting locations , keep lookin' and you might find somethign new, trying to discover every location on the map to try and discover the fifth location.