First off Askmrrobot is not great. its alright for DPS, but for tanking its misses some of the important parts about how our stat priority changes as we gain stats. Also missing enchants are missing enchants, its kinda like turning up a garage asking if you can get better performance out of the car by tuning up the engine whilst ignoring the fact one or more of your tyres are flat. your Gear is a little behind the curve at the moment, most people having been farming DS for months so healers tend to expect a tank to massively over gear the 5 man content.
Warrior tanks first gearing priority is reaching 102.4% CTC (block chance + parry chance + dodge chance + 5), at this point as long as you're not being hit from behind mobs will never land a successful hit, the best they can hope to achieve is that their attacks will be blocked. this makes warriors damage intake a lot less spiky.
Stacking mastery is the best way to do this and you should keep your parry and dodge rating amount eqaul whilst doing this. Before reaching this point you should be gemming Fractured in Yellow sockets, Keen in red sockets and Puissant in blue sockets, and it if the socket bonuses aren't mastery it may be worth ignoring them and gemming pure mastery. Generally if a piece doesn't have mastery on it you should reforge something to mastery, generally you should reforge from Haste before crit before Hit before expertise before dodge or parry
the general stat priority is;
Mastery>dodge+parry>stam>armour>>>>>>>>>>>everythi ng else
Once you've reached 102.4% the stat priority changes to be;
Stamina>parry>dodge>mastery>armour>>>>>>>>>everyth ing else
Currently you are below 102.4% by a little over 6%, you ideally want to find 733mastery rating. A good source would be replacing Veil of Lies, until you hit 102.4% static stam trinkets aren't your friends, even if they proc mastery. I know they look good on the epeen, but they really should be replaced ASAP with a static mastery trinket. The one form TB is easily obtainable from farming the dailies and despite its 359 ilvl is still the best choice for some T13HC encounters. Alternatively theirs a drop from Beth'tilac in FL and the Avengers of Hyjal Rep str DPS trinket is has enough mastery that it shouldn't be passed over just because its not aimed at tanks.
I see you don't glyph for Demo shout? Are keeping it up 100% of the time? if not why not? it along with the Thunderclap Debuffs should be up 100% of the time , together they offer a 28% damage reduction against boss melee, which on almost every fight is the single largest source of your damage taken as a tank (unless you stand in the fire a lot, which you really shouldn't) and on bosses like Morchok or Madness or blackhorm are vital at shrinking tank killers and raid wide damage spikes.
Really you ought to be maxing either Incite or shield specialization or both, not maxing Incite kinda infers you don't get nearly enough rage, dropping points from shield specialization kinda infers you're more than happy with your rage gen. Incite is a ridiculously good talent. Personally I'd drop gag order, its a redundant talent for PVE, and max both incite and Shield Spec.