Much of the paladin's fearsome aura can be attributed to one freak point in the game's history where the retribution tree was fixed to become viable and abilities such as Avenging Wrath and Divine Shield could be used at the same time. It was a glorious time for paladins and a terrible time to be any other class or any other spec for that matter. Blizzard has done much to curb a retribution paladin's ridiculous burst output since then but the stigma remains and retadins are still among the most feared types of paladins on the battlefield.
The irony is that retribution actually has the lowest survivability of all three specs and are the easiest to kill. Retribution does not have as many tools as either holy or protection and must always make strategic decisions regarding a The Art of War proc, whether to use it offensively for an instant cast Exorcism or defensively with an instant cast Flash of Light. While they move faster on average than other kinds of paladins, they have no other mobility tools other than the Hand of Freedom. It should be clear by now that Hand of Freedom is pretty much the only free movement spell that paladins have. They cannot close distances except through stuns if they are within range, or by wasting a Repentance. Retribution paladins are so eager to get within range that they will not hesitate to cast Repentance despite a one minute cooldown.
Most retribution paladins will keep on the offensive, attacking and hoping that their burst damage overcomes their opponents' defenses. Many will use Avenging Wrath even while at a distance while closing in. These will be indicators of your opponent's skill level. While retribution's burst is considerable, it is no longer at the point where simply attacking and using stuns blindly will overcome enemies, especially under the new Resilience environment. The good news is that many players of lesser skill gravitate towards retribution because it's easy -- there are so many instant cast abilities that don't require much coordination to use. Judgements, Crusader Strike, and Divine Storm are always used when they are up. Use this anecdote to your advantage.
Wait for Avenging Wrath. If you are able to dispel it or crowd control a paladin with it up, you take away her greatest strength and open up for an attack when she is weakest. Kite as much as you can, although retribution paladins are experts at dispelling magical and poison-based snares by necessity. A retribution paladin has no ranged attack that should cause worry, as Exorcism normally has a cast time and a retribution paladin that can't hit anything won't proc The Art of War. Hampering their mobility upsets them more than it will any other kind of paladin.
Better retribution paladins will fight defensively, saving much of their cooldowns and conserving their mana. They will almost always have Sacred Shield up and Divine Plea whenever it's available considering their small mana pool. Bait these players as much as possible by making them think you're vulnerable. Paladins have nothing against stuns except a talented Hand of Freedom and a Blessing of Protection (or Divine Shield) which they will be loath to use. Classes that can open with a stun can do it to bait a trinket or a Hand of Freedom, which will leave them open to subsequent forms of crowd control.
Be wary of using abilities such as Metamorphosis or Lichborne, as most PvP paladins will have Turn Evil glyphed to be instant. They have even fewer solutions to heals than protection paladins and have no offensive dispels, so classes that can heal and put up defensive shields or HoTs should be able to handle retribution's assault with relative ease. Retribution only has Hammer of Justice, which should be removed with a CC break. After that, healers can freely cast even long cast spells without fear of interruption as long as Repentance is on cooldown. Smarter retadins will save what little interrupts they have against a healer in the hopes of keeping them from spellcasting long enough to burn them down. Don't fall for it.
Disarm effects work well against retribution and a vast majority will not have a shield switch macro and use Shield of Righteousness. Dismantle works even better, as even prepared paladins will not be able to equip a shield. Weaponless retadins won't be able to use a majority of their abilities and will be forced on the defensive. Pursuit of Justice will reduce the duration of disarm effects, but it should be enough to slow them down.
Knowing that retribution paladins are only really deadly up close -- and not even so much against classes that can heal themselves -- should be key in defeating them. They have a limited number of CC breaks and their most important ones will leave them susceptible to further attacks, and aside from Pursuit of Justice have no speed boost to close gaps.
There are a few other tools in a paladin's toolbox that will be seen in PvP. Hand of Sacrifice is a clutch spell that Arena veterans use to break CC on themselves, but isn't a natural response for most Battleground or world PvP paladins. Lay on Hands also sees less use now that it confers Forbearance and the thirty second lockout from Avenging Wrath, but is still available to use as a last resort for desperate paladins. Be confident in the knowledge that if you see this ability used, the paladin is running out of options and is an even easier target despite getting back to full health.
Paladins may be the among the most resilient classes in the game, but they are far from invincible. Well, they're invincible for only twelve seconds at a time, anyway. Just keep in mind that once those twelve seconds are up, that is when a paladin is weakest. Always watch out for when the paladin blows specific cooldowns as mentioned in the first part of this article. Strike fast, strike hard, profit.