Post by Phototropic
I wouldn't say that the gemming is bad per sé... Stamina isn't as good as it was in WotLK but it certainly isn't a bad
Your parry is much higher than your dodge right now... Due to DR being even on the two, you'd probably gain from reforging that until they are as close as possible. Whilst on the subject of reforging, you've changed some crit to hit... Tankadin's currently have no real use of hit as threat doesn't appear to be an issue should you be doing most things 'right'.
As with hit, you shouldn't really need to enchant for expertise... More is obviously better but, currently at least, avoidance/mitigation is the way forward.
Work on rep for a few extra epic items and, of course, your head and shoulder enchants.
Pursuit of Justice is a mighty-fine talent but there are better available to tanks that you haven't picked up. 2/2 Reckoning, as previously mentioned, is definitely a good idea as it no longer inversely scales with gear... ie. since Cata, it's good. And, out of personal opinion, 1/2 Hallowed Ground is far better than 1/2 PoJ.
Glyph of Judgement should be replaced by HotR, unless you only ever use Crusader Strike and never, ever AoE tank. Glyph of Divine Please should be swapped out for Holy Wrath due to the Dragonkin and Elemental stun being awesome... If not that (or instead of Dazing Shield), you should most definitely above all else by using Glyph of Lay on Hands. As for minors, if you can spare the gold, it probably a good idea to get Might/Kings/Truth for the decrease mana consumption in order to speed up down-time pre- and inbetween encounters.
I know I don't have the best gear, gems or enchants but I feel my spec is a suitable example for at least an average player to take note of for reference: