~ Potential spoilers ~
The NMA forums have unearthed details and impressions gleaned from Canard PC magazine on a quest at REPCONN given by Boone, involving cultist ghouls, Stealth Boy-addicted Nightkin and a human scientist who believes that he's a ghoul. After failing an initial combat-based approach, the player managed to use the Courier's speech skill to diplomatically solve the entire, very detailed, quest, and stated that it was even possible to turn each faction against each other. Promisingly, the writer of the preview is a big fan of Fallouts 1 & 2 (he despised FO3) and was very impressed with what he saw from four hours with New Vegas, highlighting the game's quest design, dialogue, characters and music.
Translated by HawK-EyE:
Note however that the journalist did make a mistake concerning the erroneous existence of Vault 69 in New Vegas, but there does seem to be a hint that one of the in-game vaults will be occupied by an as-yet unknown tribal faction. Personally, I'm hoping these guys are descendants from Sulik's tribe.