I feel that there is lots of things missing in the game:
There MUST be a love story, will not go in detail on this section BUT the game totally missing out on this part
Game storyline is pretty basic in in itself go kill that and that. However, I feel like there is should be missions which are COMPLICATED in structure. What I mean is not go do point A - kill everyone, point B - report back. More, than one step to accomplish it. For example:
Step one, 'love twist in a story' Enclave capture your significant other and they will kill her unless you get rid of ghoul city in order to get an atomic bomb.
Step two, 'repair mission' convince ghouls to team up with humans in order to protect the city from invasion of death claws, in order for ghouls to agree you have to repair their energy station and to get parts for it you have to do bunch of side quests. While searching for parts to repair energy station you encounter deactivated ROBO - plant.
Step three, 'science mission' reprogram and activate the robots to invade the city which is being protected now by humans and ghouls!
Step four, 'speech mission' now when ghouls defenses are weak its time to invade the city of course with a help of Brotherhood, so you complete a lot of side quests for Brotherhood in order to become one of them, tell brother hood leader that ghouls about to drop atomic bomb. Than you convince a leader to attack the ghoul city. Now that when you invade the city and all ghouls are dead. Enclave show up, big fight happens between Brotherhood and Enclave while you detonate the bomb and get out of there in less than five minutes, explosion is killing EVERYONE!
Step five, now you get to choose side report back to enclave saying Brotherhood kill em all with atomic explosion or vise verse report back to Brotherhood saying the same thing.
As one can tell this script which I come up in 5min is already more complicated than any of the missions in Fallout 3, which lets face were pretty basic, there is no element of surprise so the excitement of the game story wise is really low.
You must work on storyline in order to make a game EPIC. Develop it more, maybe next time even make it Mature content since the players who played original fallout 1 & 2 grow up now and previous games had way more explicit content which generated twice us much excitement storywise.