Idea: Argent Guild

While it might be true that you have to stay in specific areas if you went for the idea it might not last as short time as you think.

You could chose between a number of locations, Northrend or from Wetlands, going up to Ghostlands, every thing between these two places are yours to Roleplay.

If you went for Nortrhend you would meet the Freelancers and the Frozen covenant, including some other people I have no idea who is..
If you chose the Plaugelands you would meet Dorothee and those people. Personally I em planing out to re-create the cult of the damned guild I em just going trough every thing to make sure it is alright.
Getting most of my ideas from the Prologue server thought, since they are doing a great job at it.

I cant decide if I want to make a silverhand guild or a priesthood.