2.0 was the patch of protection. Looking at talents it wasn't a gigantic buff. A few percent mitigation here, some stam there, a minor mechanical fix to a few talents. The real magic is more subtle. You won't notice it immediately. It's really a bit dull. It has no flashy graphics and won't give OMG HUGE NUMBERZ!
Spiritual attunement transformed paladin tanking. This was the ability that made prot a real tanking tree.
Tanking gear without class: Warrior was the second big change that isn't really all that amazing looking back. Two years later, it's hard to imagine a time when if you were not a warrior you did not have tanking gear.
This is the time of less-than-amazing changes for ret. Divine Storm was the eye candy, but in the end, it's not the thing that makes it all work.
Judgements of the Wise transformed ret paladins. Oh sure, it's been nerfed heavily, but it is regen. Mana regen is serious business, just ask any caster. This is what will allow ret to DPS for more than a few minutes and what will ease the burden of needing intellect and mana/5 on gear.
Sheathe of Light should be renamed "You are a hybrid." This is the talent that makes ret heals worth a damn. This is also the talent that makes their heals worth more than a damn.
Nerfs hurt, but it's the few changes such as gaining regen or SP that remake a spec. This is the time for retribution to gain even more acceptance, and acceptance beyond a 3% crit debuff.