We've already read the PSM3 Fallout: New Vegas article, but for those who haven't (or don't want to spoil any part of the story), CVG (PSM3's sister publication) has posted this bit highlighting how fleshed out the Fallout: New Vegas world is going to be:
Players will be able to see the effect their game choices have on the world in Fallout New Vegas, says Obsidian.
Project director Josh Sawyer, speaking in the latest PSM3, said, "we want to make sure that the people in New Vegas have really fleshed-out motivations, and that players can interact with them and get meaningful results from their actions.
"When it comes to the end of the game we want players to feel like they shaped the world."
This will involve multiple endings, branching mission structures as well as various player choices throughout the game, says Sawyer.
"Every dent you make in it, or kindness you show it will have consequences that you'll actually be able to see in the plot, the environment and the characters that live within it."