Zen over at Zen Tanking (http://zentanking.blogspot.com/), has a fantastic blog. His latest post is about alternatives to the cookie cutter 0/49/12 spec that most Tankadins run.
I don't run a 0/49/12 spec. My spec is a bit different 8/41/12.(http://www.wowhead.com/?talent=qVhZVMtIxcdMMqzVbx).
I lose Reckoning, Precision, and 1 handed spec, and in its place I pickup Divine Intellect, 3/5 Spiritual Focus and Guardian's Favor, and Improved Concentration Aura.
The nice thing about giving up Precision, and 1 handed spec is they are passive. You never see them working or know exactly what they did for you. Its not like the game calculates a miss by 3% and then puts "PRECISION" on your screen instead of miss to let you know Precision was what made you hit and not just dumb luck.
I do miss reckoning, but only when I solo. As a tank, I want abilities I can control and count on. Procs like Reckoning and Redoubt are gravy. I always work under the assumption they won't be there.
The goal of this build is to be a great tank. My Resto Druid nicknamed me Cinder as in cinder block, and I main tank for our Kara runs. We are just about to begin attempts on Curator.
But the goal is not to be only a great tank but also be able to heal for my Arena Team.
Readers of my blog have probably seen that my guild, Heroes Inc, is a rather odd guild in that we don't concentrate on one area of the game. We raid 1-2 nights a week, and PVP (Arena, BG) 1-2 nights a week depending on what weekend it is.
This spec allows me to contribute in both efforts. Would I be a better PVP healer as a 41+ Holy Paladin sure. Do we lose matches, or Battlegrounds because I go out of mana or can't cast fast enough. Probably. But a Holy Paladin won't be able to stand in front of Attumen, much less Curator in his build.
It also helps that I've gotten some decent Holy gear from doing PVP. I have two pieces of Season 2 Arena gear and 1 piece of the Battleground epic set.