Aura Cooldown..or rather, seperate cooldown.
Check this thread out. I've always supported removing global cooldown for auras, and instead giving them their own seperate one. It just...makes a lot of sense. It would definetly persuade me to switch auras more liberally. I hope Blizzard will realize this small change is for the better, as I can't think that it'll be in any way overpowered, really.