Atonement will now heal for 80% of the damage done, down from 100%. The self-heal part remains untouched.
I thought they'd try to tone down atonement a notch, but not sure if a flat 20% is appropiate. It is fun in LFR where you can heal everything with Atonement, but in an actual raid scenario there are better tools to use when you need real output quick, specially if you have enough stacks to pop AA already. The net impact might not be that huge and just encourage using other spells more, but what is everyone's opinion on this?
On another note, Mass Dispel is also getting nerfed to not be able to "remove Magic effects that are normally undispellable" (aka, bubble/ice block) unless you take the new Glyph of Mass Dispel. Not as impactful on PvE, but it makes my Shadow Priest sad for PvP <.<