I am coyping my post from the WoW forums since I know some people don't bother reading those and would love any additional input. If you do read and post in the WoW forums and have something constructive to add, please do it there so it is more likely to be read by Bliz .
This is a purely PvE discussion, so please do not bother me with ZOMG, PVPZZZZ because balancing in PvP is even more obnoxious than in PvE and these changes may be disliked by the PvP community, but I am sure plenty of other people have much better ideas on fixing disc PvP.
I have played disc almost exclusively since Ulduar and have learned to handle the spec, regardless of what has happened to it. Sure, sometimes we are terrible and sometimes we are way to good. Any disc priest with a brain knows how OP disc is at the moment and it of course needs to change.
Spirit Shell started out as a really weird idea that not a whole lot of people liked, then it was changed and more people began to like it. Then it started getting usage in raids and it was great. Then it got buffed and caused it to turn in to its current problematic incarnation. Now the proposed changes might handle a bit of the problem, but just seems a bit more like a band-aid fix rather than an actual fix. Part of the problem in trying to fix SS is that it heavily relies on PoH which is very antiquated and sometimes inefficient.
I think that SS should be changed to a 3 minute CD that is still affected by mastery, but is changed in terms of how it is applied. I think that it should work similar to Revival and should just instantly shield all targets within 40 yards for X amount (increased by mastery, obviously) for X seconds. This way, Disc priests could still prepare for moments of high damage, but would feel more like a real raid CD, versus something that we have to work in to our toolkit every minute in order to be effective.
Seeing that it is the current intent to nerf the effectiveness of DA stacking via PoH, and the datamined changes seem to show that this is no longer possible. (Granted, these changes could be misinterpreted and of course aren't definite). Perhaps PoH could now be changed to be a smart heal and isn't restricted to the targets party.
There was also mention of giving Disc another AoE spell and it is hard to think of another spell that wouldn't be overly similar to current spells held by other classes. However, there is a spell in Rift that I rather enjoyed when I played it (who knows if it is the same as when I played it) and it was called Downpour. The spell basically was a 2 second cast that then put a buff on the caster and it caused it to rain down healing on them and nearby players for X amount over Y seconds, but followed the priest around, like a cloud in a comic. It had a decent cool down, was about 10 seconds I believe. I think that something like this could be worked in to the disc toolkit and be rather fun. Seeing that we are healers of the light, it obviously would have to be a bit more heavenly inspired and perhaps look like beams of lights beaming through the clouds or something.
"Heaven's Light pours down upon the priest, following them as they wander the path. The light heals the priest and all friendly targets within 12 yards for X amount for Y seconds. 10 second cooldown. Costs 26,000 mana. 1.5 second cast."
I think that adding in a new spell and implementing these new changes to PoH and SS would make disc much more fun. Bliz has said that they hate when disc turned in to PWS spammers, so they tried to discourage that, but then we became SS spammers. With the current SS nerfs and changes to PWS on the PTR (provided they are correct, of course), disc is going to be in a weird position, we'll value mastery less, which in the end, just negates the idea that we are supposed to be absorption based healers.
These suggestions might be hated or loved, I am not saying they are the best idea, but I just thought I would throw them out there and see what other people and perhaps what a blue might think