i believe the dev's have already stated, that down the road, they will make different ruleset campaigns, based on user feedback
now ill admit i have no idea when down the road is
edit: the main reason SWTOR open world pvp(illum) failed, is that it is impossible to have good open world pvp, and instanced pvp with rewards at the same time
the secondary reason illum failed is that 2 faction pvp doesnt work very well, its to hard to balance population imbalances
if people can que from anywhere and get guaranteed action in a few mins that is guaranteed to give rewards,
they will always do that, before going to open world and maybe finding a good fight that they maybe will win so they maybe get rewards
heck even i do that, and i do not like instanced pvp and i love open world pvp
im not sure if 'open world' pvp will work in this game, mainly because its not really open world, because of the mega server, they simply cannot make it so everyone is in the same instance of cyrodill, and while the different cyrodill campaigns are persistent for 90 days, its just not the same when people can be guests in other instances if they are taking a beating in their main campaign, and they can even change campaign for a fee, this im afraid could ruin the "open world" pvp