Ausir over at The Vault let us know about a blog entry that he penned about some of the curiosities that can be found within Fallout: New Vegas' recently released Dead Money addon. It's pretty obvious that some of these nuggets form the basis of what we'll be seeing in future expansions:
The courier who wore the flag of the old world is most likely a reference to Ulysses, a companion character that was cut from the final version of Fallout: New Vegas. On the card that came with the collector's edition of New Vegas, he also carries a flagpole, a weapon that can be found in the game's files as Eagle Flag Pole. Chris Avellone stated in an interview with Lightspeed Magazine:
(There's a character on one of the trading cards, Ulysses, who was supposed to be a companion. Oddly enough, tearing him out of the game was almost as hard as putting him in because companion scripts touch almost everything (and he also was a complicated character in terms of some of the hooks into the storyline). Maybe he'll come back at some point. I miss him.)
Additionally, Dead Money was first hinted via in-game graffiti. The textures for these graffiti are in a folder in the game files called "nvdlcgraffiti", and all the textures share the filename "nvgraffitisierra". Interestingly, this folder contains a number of other textures, sharing the filename "nvgraffitihonesthearts". These read:
"Where's New Canaan, anyway?"
"The Burned Man Walks!"
"Joshua Graham Lives!"
This implies that one of the future add-ons will be titled Honest Hearts and will feature Joshua Graham, Caesar's former right hand, who is also known as the Burned Man, as he was set on fire and thrown into the Grand Canyon for his defeat during the First Battle of Hoover Dam. New Canaan is another location that was originally meant to appear in Van Buren - a Mormon town that Graham originally came from.