So I was thinking, which is always a bad idea, mainly because the hamster gets tired, and I use too many comas. I think it would be cool if Shadow Priests were able to get an ability they could use on a 10 sec cooldown that would make their next ability do AoE damage. So you could change Mind Blast to go from single target to AoE, or Mindflay from Channeled to instant damage. Of course you would blow a Global Cooldown to get these effects. I enjoy the Soulburn concept for Warlock, and sort of wish they would do something similar for Shadow Priests.