Now when the new expasion arrive I tho of a new idea to bring up the world pvp in the cities (Stormwind and Orgrimmar).
If you look at the big gate in Orgrimmar that it's alot of doors that can go down from the roof. My idea were if they could work when allys raid Orgrimmar. When a certain number of allys (maybe 20+ or something) go into Durotar the gates close and you can teleport yourself into the town (like in Isle and SoTa), and you can walk up in the towers and the walls so you can attack the allys. And the allys who attack the town now have to destroy the gates. It should be the same with the back door and that one should be more guarded.
For Stormwind you should be able to close the big door and you can walk up on the wall so you can attack the horde that is attacking the door to get inside ( there you can also teleport into the city).
Also when the exapsion come out when you now can fly in Azeroth there should be alot more guards that spawn around Garrosh and Varian and in the city, there should also be flying guards in the air that will nock the players down (like in Outland when you fly over the other faction's town) but the debuff should be alot shorter and deal more damage.
This is just an idea and I just thought of it. Sorry for my bad english :/