Assuming they do it again, place your bets on where the BL2 hunters are gonna be
I bet you'll have to find Salvador's remote-ass village in order to recruit him to your cause
If I remember correctly from the UE4 tech demo, they said that there will be different planets you could travel to and whatnot. Considering it's basically taken them 5 years to develop this game, I think we can expect some serious technical improvements
What I'm hoping for is extremely large maps (essentially open-world RPG type stuff) on a plethora of different explorable planets and moons, but I might be a little too optimistic here