since the new icecrown patch i seem to be taking a canny bit more damage in certain heroics for some reason where as before the patch i was indestructable :P, im just wondering if someone could take a look at my gear/glyphs and such and suggest any changes
I'm assuming your using Lavanthor's to trying to reach unhittable which your not quite at, I'd upgrade that trinket swapping it out for maybe a glyph of indom to stack EH, or Ick's thumb if you want to stack avoid. Assuming 100% up time on Sacred shield and Holy shield with divine plea always active, improved righteous fury and devo arua along with smart usages of divine shield it should almost ensure your not taking much damage at all. I'd respec to a slightly more agressive ret tree curve I use the 0/53/18 build myself, glyph sense undead and always leave it on unless your fishing.
Also remember in the ICC instances almost everything is undead... insert holy wrath into your rotation giving you a nice 2-3 second breather of 0 damage every time you pop it off in the middle of mob pulls. Do keep in mind there are more casters in there though and we dont have a lot of defenses against magic damage so do your best to silence, stun and kill the casters asap to minimize incoming pew pew's and make sure your healers are buffing you accordingly with totems, blessing's, drooid buffs etc, to raise your resistances against the pew pew's.
Like Suicyco said, there is a lot of magic damage in the new instances which tends to be a prot paladin's weak spot (lack of interrupts and silences). I would swap out Lavanthor's unless you need a shield block set for whatever reason, the Glyph is a great trinket but I really dislike Ick's Rotting Thumb - the on-use is great, but dodge is really inferior to stamina or armor (especially given all the casters in the new instances).
As far as an armory critique, you have pretty nice gear, everything is properly gemmed and enchanted. The only thing I take issue with is your spec: try 53/18. Divinity is not worth the talent points (it mostly contributes to overheals, and even in the rare situation where it contributes to effective healing, 5% is not a lot), you only need one point in Spiritual Attunement to keep your mana bar full, and Crusade is a superior threat talent than Seals of the Pure (unless you're focusing on Ulduar, where very few mobs meet the criteria for the full 6% damage). And the minor glyphs Sense Undead and Lay on Hands are fantastic. (the third minor glyph is kinda useless, personally I use Blessing of Kings but it doesn't really matter)