You have more than enough unbuffed HP, so for some of those red slots, like in your gloves, I'd place a Guardian's Twilight Opal (expertise/stam). Secondly, back off on the parry gems and defense gems. You don't need them to reach the cap, so instead use either hit/stam gems or exp/stam.
Your spec as well looks a little weird. You have talents like Puncture which just isn't worth it, as well as 1 point in tactical mastery? Maybe something like Talent Calculator - World of Warcraft would be better that has Impale/Deep Wounds.
If you only have 5 points in Fury, it should be 3/3 Armed to the Teeth and 2/5 Cruelty.
The first that jumped out at me was your AP is very very low. Att will raise it almost 400 AP. At your gear level that's close to a 20% boost!
3 points in puncture are either wasted or mean you could be using a better rotation. These days prot warriors don't throw Devastate as much as they used to.
Rampart touched on it, but 8/12 parry gems are very poor for survivability. You have 3 which gives you a little less than 0.5% before diminishing returns, which your parry is already being hit severely by.
If you changed all 3 of those to 8 exp/12 sta gems you would gain almost 2 expertise. That would give you -0.5% enemy dodge and -0.5% enemy parry. That's roughly a 1% dps increase from 3 gems.
That said though... in my experience a respec and a few gem swaps aren't going to magically fix any threat problem you may or may not have. They'll make a difference, but it might not be enough on their own. Take a look at this excellent compilation: especially the threat section - http://www.tankspot.com/forums/f56/4...tml#post191505