Well while FO1 had a few and cant remember much on FO2 having them but repeatable quests like caravan guard, debt collector, bouncer and trader etc... Perhaps have it that doing some these quests the player losses reputation in soem factions while gaining some in others to add to the choices and conseqences
More city factions, kinda like the kings but they had proper rivals had to take out etc... with out making it regional like FO2 in the city new Reno where had diffrent mafia types gunning for power in diffrent ways (though Honest hearts look like it will do that with tribes)
Also more in depth deatures like in FO1 could borrow money from not very nice people and then have be hunting you if havnt payed.
other ideas could be perhaps be taken from Van buran(canceled fallout 3) like weapon reserach and devlopment where find scematics for powerful items what need high science, supplies and labs.
Also while bethesda is making FO4 and a good chance it will be more East Coast then West coast I hope Bethesda stays away from the West till they learn how Fallout works more (FO3 was a nice first try but baby steps, leave West coast the people who helped write and design it)