Get helm and shoulder enchants.
If you get
Arcanum of the Stalwart Protector - Item - World of Warcraft from Revered with the Argent Crusade and get the 30stam/15 resil PvP enchant to your shoulders, you will get uncrittable.
Otherwise you seem to be going in the right general direction with gems/enchants. As krc said, defense first, then go for stam, the more stam you have the higher end stuff you can tank. I don't know how much or how far you're wanting your warrior to tank, but stam is always a safe bet.
Good trinkets, that's a plus. Meta is correct too.
For gloves I'd suggest 240 armor, however using the parry/threat enchant is alright for beginners, especially if you're having threat issues.
For Boots I'd suggest switching to Tuskarr's Vitality, the utility of the runspeed is invaluable imo.
Your spec/glyphs are close to immaculate. The only thing I'd change is putting 3 points in shield spec into focused rage, but tbh that comes down to playstyle/preference. I'd also change the sunder glyph and instead get vigilance, last stand, or shield wall. The shield wall glyph goes really well with imp disciplines imo.
I'd also focus primarily now on getting a new weapon. Running HToC5 and H-UP every day can get you a very solid entry level weapon, there's also a new one I think from the Argent Tournament rep, the Axe of the SIn'jin or something.
So I'd say streamline your gemming, make a few minor adjustments and get a new weapon and you're well on your way! Things look fairly good.
Oh and for weapon enchant, mongoose is probably one of the better entry level ones but for higher end I'd suggest bladeward for avoidance or blood draining for EHP at higher levels.
