I've been playing this game since the very tail end of BC, and regrettably I went from 1 to 80 in prot spec. In that time though, I did learn the ins and outs of Paladin tanking. The feeling of, as i'm sure most people have said, "Rounding them up and concencrating" was a great feeling that never ceased to invigorate. Now I remember when there was diversity in the tanks. Warriors ruined armor on their single targets, and could put out stupid amounts of DPS, Paladins, as I have said, were AOE powerhouses, bears had ridiculously high health and armor, and the D.K.s had their active regeneration. Correct me if I'm wrong, but the D.K. active regen came from a combination of lifesteal attacks, blood tap, and sacrificing your ghoul.
Then Cataclysm, and for the same part Mists, comes along and turns everything up onto its ear. All of the tanks kinda got squished together and turned us into detuid warridins. I myself felt as though part of what made me enjoy Paladins was kinda taken away, mostly the numerous cool-downs I had that would help blocking. Sure, things were still good though. I cleared every raid up to Dragonsoul, where I got most of the encounters down.
Mists, for the lack of better words, was the trainstopper. I had not heard of this "haste build" that had been so popular, and when I was searching for a new guild ((old one imploded due to pandas)), I had found what must of been one of the best on my server, Wyrmrest Accord. When I had joined up and started clearing Throne of Thunder when the G.M. noticed I was using an avoidance build. He said that I should be using the haste build. At the time, I had no idea what it was, so with the help of the guild, I re-outfitted my character for haste tanking. While it worked good on paper, there were multiple problems with it. The guild wanted me to have like...20k HPS I think it was. They also wanted me dealing at leat 50K DPS
Now, It's already a fact people are going to start calling me a whiner over this, but last I checked, I'm a tank. I poke the dragon in the eye so it doesn't eat the mage for breakfast. My job is to keep stuff attacking me so that others don't get slurped, not to heal or deal damage. With the haste build it made tanking more spotty, and it lead to me getting killed by stuff I could of normally took on the chin with the avoidance build. I can see why the active regeneration would work for some people, but there's a difference between hitting auto attacks and procing seal of insight with battlehealer, and hitting two buttons with a relatively low CD and healing practically up to full as a D.K.
Which leads me to to WoD. We already know that item drops now will be optimized for the player, rather then having stuff drop everywhere. Not only does this mean that gear grinding wont take as long, but it also means that there will be set stats for Paladin tanks. The battlehealer nerf from last patch made it useless for me to solo anything, since it doesn't proc on me anymore; and correct me if I'm wrong, but they did nerf Sacred Shield so it was significantly less effective for Prot Paladins.
In the current state of things though, there's no way to determine where Pally tanking will go. We already know that Hit, expertise, dodge and parry are out. I would take a wild guess and assume that some other passive bonus will be acquired when the player hits a specific level, like how paladins now become uncrittable by enemies within the boss level rage once they acquire Sanctuary. With the removal of Reforging as well, I would warrant pretty good speculation that Haste Tanking is dead come 6.0.