Well we already know there is a new race we will encounter, a race capable of riftrunning. In the meaning of a rift between worlds, that could mean they are able to 'run' from one world to the other, where others (among which your avatar) is unable to do that.
Also we are supposed to 'save' these riftrunners from something as part of the storyline.
I can only assume that during the course of the game we will learn 'riftrunning' also.
Anyway as they are a new race, they will have to live somewhere and will have their own economical system, which probably includes shops and such and a reputation is relevant then. Also you might not be the only one who is send to this world (either before you or after you), which might account for you meeting NPC's from <img src="/ubbthreads/images/graemlins/div.gif" alt="" />.
There might be 'evil' characters where a low rep makes them not attack you, but consider you as one of them and give you decent prices in their black markets. That same low rep creates hostility amongst the good guys and drives up the prices in their shops.
