Power Word: Shield, was a major reason why Discipline was viable in the Mortal Strike rampant, PvP environment of wotlk. While other healers had to cope with the 50% healing debuff on all healing spells, Discipline could fall back on mitigation (which ignores ms), to supplement their weak healing. With the removal of 50% Mortal Strike and the corresponding damage/health pool increase, Discipline lags behind other healers. The removal of Dispel resistance, while a good change, also hurt Discipline survivability in PvP and further serves to weaken Power Word: Shield. While I am supportive of these play style changes, they need to be backed up by buffs to the other areas in the Discipline Priest’s healing repertoire.
The 20% buff to Heal, Flash Heal, Binding Heal and Greater Heal is definitely a step in the right direction and a clear indication that the developers understand the issue. However, these buffs will not fully relieve Discipline PvP problems. Discipline is a ‘tanking healer’. While Druids have travel form, Holy Paladins have Hand of Freedom and Shamans have Travel Form, to remain manoeuvrable, Priests rely on team members to peel melee opponents. With the new abundance of interrupts, this old style of Discipline healing is perhaps no longer viable. With a melee training you, heals like flash heal and greater heal become unwise to cast without first, ‘juking’ the enemies interrupt. Unfortunately, Priests cannot keep themselves alive using their instant cast cooldowns as they once could and spamming casts will not work now that every dps class has an interrupt. Thus, the only solution I can see is to give priests an escape mechanic.
Make Fade remove movement impairing effects, increase the cooldown to 2 minutes—give shadow a way of reducing this cooldown back to 30 seconds. This would give Discipline an escape cooldown yet, perhaps allow them to maintain their persona as 'tanking healer' while still allowing them to get a way and heal when it is really necessary.
Put Body and Soul into the Disc tree (minus the poison removal). This change again, looks to give Discipline a way to get distance on melee. It is also flavourful with Disciplines emphasis on Power Word: Shield enhancements.
Add a 5 second aura mastery effect to borrowed time for the next 2 casts. Again a Power Word: Shield change, this would let Priests spam some heals without risk of being interrupted.
Give Discipline a Dispel protection talent—i.e. whenever Power Word: Shield is dispelled; the priest gains a buff that reduces all damage by 10% for 10 seconds. I didn’t put a huge amount of thought into the numbers on this, but the rough idea would help solve the issue of dispel training on priests.
I hope some of these ideas prove useful and that this post helped to shed some light on why Discipline PvP is struggling currently. If you have any comments criticism or suggestions, feel free to post.