I don't think the answer to the problem is separating the player base onto another server or magically wisping them away to a locked map where people play against each other in smaller groups.
I rather like the DAoC idea that someone mentioned above me. The solution needs to be incorporated within the main game somehow. Make it so outfits own their own bases on maps different from the bases that you incorporate into the game already. Then have something of a lattice type system that connects to the outfit base maps. An empire would have to lock the connecting continent to gain access to the outfit bases and attempt to steal a relic 'Al' la' DAoC' style of sorts.
EDIT: To add, for the devs, you've got your work cut out for you in map designing in the above scenario. And don't think us PS vets still don't want enter/exit vehicle animations too!
Good job so far though!