Let me say this and perhaps people will stop crying that the sky is falling...
Spirit Shell on a 60 second Cooldown is so far and away the most powerful ability in the game its just stupid. There is no other healer that can lay down a 3,000,000 effictive heal with 0% overhealing in PREPERATION for raid damage not in reaction. Even with the PTR nerf to make mastery not effect Spirit Shell how many people actually realize that mastery does not increase the max that SS can be stacked to only the speed in which you are able to stack it to max? With AA stacks you will still have zero problems getting max Spirit shells up to trivialize mechanics in 10 man raids. In 25 man raids there will be a decrease in your SS stacking since you are spreading it around 5 groups instead of 2.
Far to often people get all wrapped up in HPS numbers when they dont even understand what makes classes amazing all the DA nerf on PoH is going to do is make our healing partners not OH so much and change the landscape of our raid almost nothing. There are a few instances like the last phose of heroic elegon where we will see a throughput hit but its not like you are going to go from being able to kill Heroic Elegon to not having that ability with this "nerf".
If spirit shell doesnt ever change the disc priest will still be the most sought after healer in 10 mans hands down nothing will come close. What else are you going to bring?
Holy Priest.....Divine Hymm and GS HoH
Holy Paladin.....Devo Aura and Sac/Bop/Freedom
Mistweaver....Revival Life Cocoon
Resto Druid...Tranq Ironbark Treeform
Resto Shaman...HTT SLT Ascendance HoH
Guess what you have good throughput and you have barrier and Pain suppression that would put you pretty even with every other healer....OH AND YOU HAVE SPIRIT SHELL EVERY 60 SECONDS!!!!!!! Nothing is even close to that in terms of raid viable Cooldowns and trivializing mechanics and lets not forget that tranq/HTT/Dhymm dont heal 10 people at once like SS however Revival does but Revival is usually like 40-60% overheal since its in 1 hit.
Any compitent healer in a compitent group understands that healing currently isnt as much about HPS as it is about surviving certian mechanics phases of a fight and aside from that healing is super boring and its so easy that I spend almost all of my time spamming smite/holyfire/pennance on the boss this is even in Hardmodes and while my guild isnt mega cutting edge we are 5/6 heroic MSV.
So could we please stop with the 4324323423 page flame threads about how worthless disc priests are about to become. If you only quantify your raid contribution by the hps number on recount/skada/wol you probably arent a compitent enough raider to even be commenting on the proposed changes on the ptr.