In my opinion, from a vet perspective, prot paladin is the most dynamic and useful of the tank specs at this level.
Durable as fuck, can dispell, can stun, can heal, decent enough movement ability, benefits from crusader and has multiple pvp talents to chose from depending on your desired playstyle (talented silence, dmg reduction, snare removal, knockback, aoe cleanse, or stacked assault). The only major downfall is the lack of an offensive snare.
Nothing against the other classes, some of their pvp talents can shine in certain situations, however I don't see any them occupying the same spot on the tier list, pvp or otherwise.