SPOILER: A quote from the second page: "In Oblivion you felt as if your choices were affecting communities, but the scope of your actions in Fallout is disappointingly limited." I happen to know though a IGN gameplay video that one quest (If you want to be a bad guy) has you detinate Megaton's Bomb vapourising the town! I think that would qualify as affecting a community.
Mass Effect 2 (Xbox 360): Mass Effect 3’s story to feature over 1,000 variations