Promote to Alliance Leader
The reason I think this would be a great feature is because if an alliance dismisses then all of the gold, the coins and the resources that alliance members donated will just disappear as far as we know. Possibly more important, all of the prestige that and alliance has earned from capturing mines will disappear as well, leaving an alliance to start all they way at the bottom of the alliance ranks if they choose to relaunch their team with a new leader. Such an event would be a shameful waste and a great disappointment to an alliance.