This might go well with the separate bounties, because if you destroy a rival holds economy, you might gain popularity in the other hold.
This latest info about the separate bounties, combined with previous comments from Todd about there being "a lot more" factions in Skyrim, suggests:
The clans that rule each hold might turn out to be separate, joinable factions...that's NINE NEW FACTIONS!! ZOMFG! :drool: :drool: