There are a bunch of things needed for holy to be viable. Here are some issues as I see them.
- Mana issues. All those instant spells you throw around are expensive. Holy Concentration is nearly useless in PvP. The spirit based regen with expensive spells is generally ill-suited for PvP.
- Poor partner healing. This is another big one. Holy priests in PvP just aren't good at keeping anyone else alive than themselves.
- Needs more crit! Surge of Light procs are important as hell. The new Inspiration would also help if you could keep it up more reliably.
- Too susceptible to stuns and silences when focused. Holy takes more damage than disc or shadow. The healing is good, but you drop too quickly when caught in a bad stun or silence.
So, to try and help with those things without affecting PvE too much, here are some suggestions:
- Make CoH get +5% crit for each missing target - i.e. if you only heal 2 people with a non-glyphed CoH you get +15% chance to crit on them (that would make the glyph more useful for 5-mans and PvP too).
- Alternatively, give CoH a significant crit-chance boost only on the target of the spell.
- Add to Test of Faith that you take 7/14/20% less damage when stunned or silenced, like
a watered down version of the elemental shaman talent Astral Shift. Deep holy builds need it, and it would be out of range of 34/37/0 Focused Will builds.
- Add Holy Nova to the list of spells that can proc Holy Concentration.
- Make some holy priest heal ignore Mortal Strike effects, like Binding Heal with Emp. Healing or Renew with Emp. Renew.
- Make Divine Providence lower the cooldown on Desperate Prayer too.
Those things would all help, but I doubt that the mana situation would be greatly improved. Currently I don't know how to fix that without somewhat more drastic changes.