In Fallout 3 you are given the option to destroy Megaton with a nuke...at the end of brokensteel, you could destroy the citadel, and yo can help ghouls kill everyone in tennpeny tower. All of these options involve dramatically changing an area or region and removing any quests for that area. so, i agree with the others that it could be nuke time for someone in the mojave. Another idea is that, maybe, you will get ulysses as a follower. I believe someone said that all of his companion codding is still in the game files....sooooo
Excuse me, but in what way this events remotelly affect the areas? Around Megaton you have radiation, but that's it, even travelling merchants still stop around town and those raiders by the school act like nothing happened. TT doesn't affect s*** what happens in the region. Broken Steel turns the Citadel into rubble and that's it, nothing happens either (worst of all, the BoS troops around the Capitol and Washingtong Monument act like nothing happened either).
The same can be said about Forlon Hope if you helped the Legion.
At least give me something like Helios ONE or Nelson, where your actions replace the dominant faction, with all the advantages and drawbacks these brings.
And honestly, I hope this talk about nuking a settlement isn't real. What sense does it make being allowed to nuke Goodsprings, but don't having the chance to nuke McCarran?