What does a tank need more than anything?

Fix Provoke so that if another tank is on top of the threat list, it sets the Provoke-ing tank to some small amount under the tank who already has threat. Too many I-JUST-GOT-TO-TANK-EVERYTHING!!! mentality from tanks in 24-man raid groups go bad. Make Shirk work raid-wide so if a tank swap mechanic is needed, it can still be done.