Zarhym (Link)

We wanted to introduce some of the changes to dispel mechanics coming in Cataclysm. Our goals were to make dispelling a little less trivial to do in PvP, and to make sure there is more equity in dispel capabilities among healers in both PvP and PvE.

Within the system, there are currently five types of dispellable (or curable) buffs and debuffs: curse, disease, poison, defensive magic, and offensive magic. An example of defensive magic dispelling would be using a dispel to free a polymorphed ally, while offensive magic dispelling would be utilizing a dispel ability to strip away an enemy’s buff or heal-over-time (HoT) spell. The main distinction between these two types is in whether or not you can target an enemy with your dispel.

In Cataclysm each healing class will be getting three out of the five types of dispels, with one of these always being a defensive dispel magic. This design makes sure that finding a healer with the ability to remove magic isn’t restrictive in building teams for Arenas or rated Battlegrounds. It also allows the encounter designers to assume, when designing dungeon or raid fights, that every group can dispel magic.

In addition, we're making the opportunity cost (what the player could have accomplished with different actions) for dispelling a bit steeper. We think the cost is too low for three reasons: 1) The actual mana cost is low. 2) You never waste a dispel. If you try to dispel a debuff that isn’t there then the dispel just won’t go off. 3) We have spells that remove debuffs with minimal input on the part of the player. 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.

As previously mentioned, we are providing three dispel capabilities to all healing classes as follows:

• Druids will be able to dispel defensive magic, curses, and poison.
• Paladins will be able to dispel defensive magic, diseases, and poison.
• Priests will be able to dispel defensive magic, offensive magic, and disease.
• Shaman will be able to dispel defensive magic, offensive magic, and curses.

There is some trade-off that is being made in making these changes and we wanted to expand on this further.

• Protection and Retribution paladins will lose their current ability to dispel magic.
• All shaman will lose dispel disease and dispel poison in exchange for Restoration gaining dispel magic.
• Restoration shaman, Restoration druids, and Holy paladins will need to talent into their defensive magic dispels.
• Shadow priests won’t be able to remove disease in Shadowform.
• Mage, hunter, and warlock will retain their current dispel mechanics.
• Body and Soul remains the same, and basically any dispel mechanic not mentioned above is currently planned to remain as it is.
• When possible, we’d like to combine dispels into a single action. For example, the druid ability to dispel curses and poisons might be a single spell with a Restoration talent that also allows it to dispel magic. This part of the design isn’t finalized, however.

As with all of our Cataclysm previews, keep in mind that any of these decisions could change when we’re in beta.