This rubric is based on my personal experience & opinions. Biases have been left out. Some specs have inexistent data pools - said specs have automatically been filtered to "Shit tier". I will note, that placement has been subjected to how successful each spec is at a minimal skill level. For example, a good Restoration Druid whom can cyclone, dispel, LOS & pre-hot easily is a tier 1.
DPS
GT: Windwalker, Enhance, Fury, Arcane, Outlaw
T1: Elemental, Retribution, Balance, Arms, Shadow
T2: Marksmanship, Frost(Ma), Destruction, Assassination, Frost(Dk)
T3: Affliction, Fire, Subtlety, Survival, Unholy
ST: Demonology, Feral, BeastMastery
Healers
GT: Restoration(S), Discipline
T1: Holy(Pr), Mistweaver
T2: Holy(Pa)
T3: Restoration(Dr)
ST:
Tanks
GT: Protection(Pa), Guardian
T1: Protection(Wa)
T2:
T3: Blood
ST: Brewmaster