Just a thought. Back when Fallout 3 came out, people complained that it was "Oblivon with guns". Now, I liked Oblivion, so this wasn't necessarily a bad thing for me, but there was a lot of black and white morality and self-contained factions (as in, the Mages and Figher's Guilds had nothing to do with each other, just like how say, the Paradise Falls Slavers were only concerned with the kids from Little Lamplight, and were totally ignored by say, the Outcasts) in both games, which was kind of a step down from Bethesda's previous Elder Scrolls title, Morrowind, which had faction quests that tied into each other (there was a lot of crossover between the Guilds and the Great Houses for example), as well as a main quest where you potentially did more harm than good. For example, if the player had never destroyed the Heart of Lorkhan, would Morrowind have been destroyed by the Ministry of Truth crashing into Vivec?
I know a lot of Fallout players might have no idea what I'm going on about, but bear with me. Also, play Morrowind.

With all this talk about how the factions of New Vegas interact with each other, and the morally grey storyline (at least what we know of it so far), it seems to me that Obsidian has listened to not just Fallout players, but has taken some of the gripes people had with Oblivion, and has addressed those as well.
Could New Vegas be an indication that perhaps The Elder Scrolls V (when it's announced) will be returing to the series' darker, more complex roots?