any news on fire/frost mages/ret pally/ shadow priest?
Frost and fire mages are both mediocre. If fire specs in to scorch and spams it for consecutive crits, instant pyros are nice, but it is tough to get enough crit to make it consistent (scorch spam on its own is weak). Arcane mages put out huge burst if they stack arcane blast charges, but that requires being able to stand there and spam arcane blast for 6 casts. It also drains your mana very quickly.
Ret paladin is one of the few specs that I haven't seen in action, but I have heard that it is pretty weak. It lacks the 1k crits that it has on live. The heals should be pretty good, tho, like on live.
Shadow is decent right now because all healing specs are OP, but its damage is bad compared to disc, as well as its healing. It literally only has mind flay and swp, as far as damage dealing spells go.
On PTR right now, since heals are so OP, the damage portions of holy shock and penance are also OP. Holy shock is critting for over 700, and penance ticks are critting for mid 300's. Disc priests hit like trucks with penance, and also have holy fire and fast cast smites.
Spirit is also very broken on PTR. Everyone at 19 has mana pools of 550, and spells cost very little mana. Unfortunately, mana regen from spirit has not been rebalanced. Healers are still getting their cata-level mp5 in combat, so stacking spirit makes it virtually impossible to go oom because spells cost so little. And since heals hit for ridiculous amounts, their effectiveness is not badly compromised by not stacking int.
Don't go crazy spending gold on spirit items or anything, though, as I wouldn't be shocked to see it rebalanced relatively soon after launch.