The item level was too high compared to the character level at which it could be used. This was updated in a hotfix on February 14.
It's not supposed to have a level 80 requirement, but it also wasn't supposed to be item level 200.
Incoming Healer Changes / Shadowpriests using Power Word: Shield (Source)
I probably don’t have the answers you’re looking for in regard to PvP, but Shadow priests already put out significant damage in PvP, and we’re ok if they’re a little bit more vulnerable as a result of this change. Discipline priests while not putting out as much damage, were still healing well and were likewise difficult to kill in PvP. As always, we’ll keep an eye out on these changes to see how they play out on the PvP end.
Generally speaking (and more to the PvE end), the Discipline tree has talents that play off of Penance, Flash Heal, Greater Heal and Prayer of Healing. It wouldn’t be strange for these priests to leverage Power Word:Barrier to help mitigate damage either should the occasion present itself. There's a solid variety of available spells to be used, and we want you to use them. Moreover we think healing as a priest will be more fun if you have to think about which spell to use rather than robotically answering each damage event with PW: Shield. Overall, we’re not reducing the power of Power Word: Shield at all, just increasing its cost and making the more efficient heals more attractive to use.
Power Word: Shield will still have its time and place and as always. We want it to be used often, we just don't want it used to the exclusion of all other abilities. We'll keep an eye on how things play out once the change is applied too.
*Someone earlier in the thread asked if this was an increase from base mana, and it is from the base mana cost.
As an aside: For those sharing constructive feedback, as always, we thank you. For those who are utilizing this thread as a means to simply complain, we hear you, but overstatements of upset aren't going to help us address your concerns. (
Power Word: Shield (Source)
We don't want Discipline priests completely reliant on a single spell or ability for everything- (as in), Shield should not be the only spell you feel worth casting. Discipline priests are still very powerful at damage mitigation and we're not trying to take away using PW:Shield on a regular basis or its value. There should still be some worth in choosing which spells to cast and when.
[...] We want people using Power Word: Shield. As others have pointed out, it's something Discipline priests do well (Damage Mitigation) and it took awhile before more people began to believe that (remember those days?). Damage Mitigation will still happen and is still important even with this change, it's just not going to be the ONLY thing that the Discipline spec is going to be using to keep their groups and Raids up. There will be heals as well. Also, in Raids, there will be more than a Discipline priest supporting the raid. So knowing the best use of your abilities in that situation is key and playing off of the strengths of other healers will be as essential as it has always been.
Again, we're continuing to watch constructive feedback even if we may not be responding to all of the questions and thoughts that have been brought up in this thread. We are definitely reading.