Overall, heals cast by players in Cataclysm will be a lower number relative to players' health than the current game. So to make the Mortal Strike debuff less mandatory but still useful in PvP, Mortal Strike will reduce healing by only 20%. All equivalent debuffs, including the Shadow priest and Frost mage debuffs, will be for 20% less healing. At the moment we aren't considering giving this debuff to anyone else, though we will certainly consider PvP utility for historically under-represented specs that use other mechanics.

some good news for us :>