Protection paladins are the best Tank for the Wotlk expansion, with great mitigation for both physical and magical damage, utility, and the best passive in the game, [Argent defender].

Rotation for Protection Paladin Wotlk

Protection Paladin Priorities

Keep Holy Shield up > Hammer of the Righteous > Consecration > Shield of Righteous > Judgement

Tips

Avenger’s Shield can consume too much mana, so use it when strictly needed for long-range Aggro or for a Silence.

Use Divine Protection, Divine Plea, Sacred Shield, Divine Sacrifice to mitigate the damage as needed, in some fights Divine Shield can be used to clean stacks of debuffs if the OT can pick up the boss, like for example Festergut.

Holy wrath can be useful to AOE stun undead mobs.