Back in the day of Yogg I had a special spec to Hit Gophers on the head Dispel the magic effects and diseases from the encounter
This allowed me to DPS as Shadow when I could, and especially in our learning stages be more mana efficient when doing the large volume of dispels that were required.
Blizz Blues have just announced changes to dispel mechanics to come into affect for Cataclysm
“We think the cost is too low…
“In Cataclysm we are raising the mana costs, making it possible to waste mana by casting a dispel when there is nothing to dispel, and removing Cleansing Totem, Abolish Disease, and Abolish Poison from the game. With these changes in mind, we are working to plan dungeon and raid encounters where dispels aren’t in constant demand or spammed in order to be successful, though some need for dispels will still be a part of the design.”
“Shadow priests won’t be able to remove disease in Shadowform”
So for the trade off - we get less encounters that require the attention to dispels that the Yogg encounter did - you can get penalised by wasting mana casting a dispel unnecessarily
Shadow Priests are going back to not being able to dispel disease which if you remember back that far. We have only been able to do since 3.08
I guess we should be grateful that we seem to be keeping Mass dispel - which remains unique ( at this point) to Priests. I am hoping that with this change to our class. That raid leaders will also evolve, and not require Shadow Priests to drop Shadow Form to Cure disease.
Blizz blues also said
“we are providing three dispel capabilities to all healing classes as follows:”
Note Healing classes. I shall interpret this as DPS ARE NOT MEANT TO DISPEL