Lots to digest in the patch 4.0.6 notes, but here's the big one:
Power Word: Shield now scales from 87% of spell power, up from 41.8%. Base absorb increased by 110%, from 3906 to 8136. Now costs 25% of base mana, up from 19% of base mana.
Now I think it was obvious that I was clamouring for some kind of buff to Power Word: Shield for while. That being said, I'm not sure that giving Discipline Priests a 29k on-demand instant heal is the solution to that problem. Compared to Greater Heal it would have 67% more throughput and 20% more efficiency without a Rapture proc. As before, Rapture procs are larger than the cost of the shield. Power Word: Shield would have higher throughput than a four target Prayer of Healing.
I guess the question is, what is Power Word: Shield supposed to be doing? There are three states is seems to be able to occupy: 1) High throughput and efficiency plus all the benefits of being a shield instead of a heal so cast it all the time instead of regular heals; 2) Mediocre throughput and low efficiency without a Rapture proc so cast it once every 15 seconds on the tank like clockwork; and 3) Useless.
The ground I think we'd like to see Power Word: Shield occupy is where we actually cast it on someone who is at low health when they are in danger of dying so that another heal can land, or on someone who is about to take massive damage to make sure they live through it, but that we don't cast it all the time as a staple heal.
I really see only one way to accomplish that, and I don't think anyone is going to like me for suggesting it: lower the duration. If Power Word: Shield only lasted 8 seconds then you wouldn't go around spamming it on people as a heal because it would fall off without doing anything too much of the time. If someone was low and you were worried about them dying before they got a heal, it would work just as well as it does now for that purpose - but would have an extra "hidden" cost that it might go to waste. If someone was about to take a big hit, 8 seconds would provide lots of time.
I'm now getting very nervous about what's going to happen to discipline priests. The more buffed you get, the bigger the nerf is going to be. Normally this kind of swing is reserved for paladins, who tend to either be overpowered or underpowered while priests have traditionally been in the middle. We may soon return to the days where discipline priests were a strange kind of healer: you are crazy if you don't bring one, and almost equally crazy if you bring two.