(Don't flame for comparisons please)

I don't know about you guys but in Oblivion one of my most favorite and loved parts of the game was the faction.. From the Arena to the Brotherhood.

It was excellent how you would grow the ranks, like becoming the champion of the arena.

I wonder if there is anything like that in this Fallout game, in terms where the factions are literally so involving that you can just forget about the main story line and feel like your actually apart of them.

Possibility? I think so.

From what I understand, the major factions are the main storyline.