I am also aware that there has been varied and sundry commentary already made on the as-written changes to shadow priest PvP. I understand that, but I'm making the thread anyway.
My thoughts, just kind of in order of the patch list:
Halo will no longer hit enemies that are in stealth.
As much as people complain, this is a reasonable change. Halo has a very large range and its ability to knock rogues/druids out of stealth in arena is a little too much. Especially given how critical to them their opener is.
Angelic Bulwark's Spirit Shell can no longer be dispelled.
This is moronic. Not the change, but the fact that this is being addressed but the fact that Angelic Bulwark itself is STILL ABLE TO BE DISPELLED. It's one of our prime self-defense talents and it's useless against any class or comp that can purge.
Devouring Plague now deals its damage evenly through its duration.
This, I assume, is geared towards PvE somehow or to reduce our "enormous burst". As it stands, it's a terrible change for PvP. This change makes dispelling DP top priority for healers and starkly reduces the chance that it will be able to deal even mediocre damage before being cleansed. (On a side note, our burst is entirely RNG, making it effectively much weaker than timed and controlled burst such as BM Hunters' spells or warriors' spells in arena.)
Glyph of Mind Spike only works from Mind Spikes that aren't instant casts from Surge of Darkness.
You know, I'm not sure why this glyph became a target. I'd always assumed that it was INTENDED to be paired with Surge of Darkness and that was the whole gimmick. Altering this glyph generates one problem and one big question: How are Spriests supposed to keep up with the huge instant cast damage of, say, mages when we have to channel or hard cast everything? And who even uses mind spike regularly except people who are leveling or killing useless adds?
Flash Heal and Binding Heal will heal for 30% less when cast by Shadow Priests.
This one's caused a lot of consternation, but honestly it's completely valid. Our heals are pretty strong right now, especially with some lucky Surge of Light procs. That's not to say that they should be balanced AROUND those procs, but we still do pretty well for ourselves compared to other hybrids.
I don't see this int he official patch notes right now, but I've also heard tell that Dispersion is able to be locked out in the Shadow school, which is BAD. BAD BAD BAD BAD BAD BAD BAD BAD BAD BAD BAD BAD.
Dispersion is our "Oh, !@#$" button and one of the primary times it's necessary for us to use it is when we're liable to get interrupted (due to being melee trained, counterspelled and frost nova'd, etc.). This is a killer to our durability and is frankly unwarranted, especially if Phantasm is also going to get nerfed. Which brings me to...
On the Overpowered Scale of 1-10, this one struck me as about a 2. And the worst part is the consolation price we're being handed, two more seconds of snare immunity. That's not the primary use of Fade anymore, Blizzard. It's a CC-killer, a survivability tool, something to keep that Chaos Bolt or Deep Freeze or Counterspell or Polymorph from going off. We neither need or want 2 more seconds of slow immunity, especially not at the cost of losing our self-obscure. I'm just not sure where the wisdom in this nerf is coming from.
TL;DR: A couple of the spriest changes are justified, but many of them are heinous and unnecessary. Blizzard needs to step back and get a handle on what's really important to our class and what it's true strengths and weaknesses are.