This is a very good idea! Now winning is kinda lame, you just don't care! I think there will be a lot of players willing to put up some extra effort / gold if at the end of the war you also get revenues for winning games (maybe in-game cash for the faction vault?).
Another must: Give android-users the same stats as IOS-users: we also want to know the attack / defence stats of the opponents we beat so we can share them. Also it seems that the android-statistics are wrong a lot of times, we for instance have 6 members with exactly the same stats according to my data... that must be wrong!
Lastly: We yesterday experienced something strange, we put down a defence leader from a strong faction and one minute later he was up again. Is this cheating or a glitch?
Lastly: Although it can be improved further, world domination is really a great addition to the game! It lets people from all over the world come together and ensures lots of fun!