Gearwise you're fine for Naxx and OS, only issues I would have are:
1. I'm not a big fan of duel wielding tanks - you have the soft expertise cap, but being parried is an issue; also hit is low for dual wield.
2. For talents - I'd take the 2 points out of Chilbanes and the 3 out of Acclimation and put them into Bladed Armor for threat purposes. Also, you may want to move points from Epidemic to Blood of the North.
3. Glyph of Disease is not great for tanking, Glyph of Howling Blast tends to be better - multi mob diseases off the bat; and, I perfer Glyph of DnD over Glyph of IBF, since I use DnD a lot for threat.
Thanks for the response Theo. I actually swapped out my glyph of disease for howling blast this morning. Couldn't get hold of the DnD glyph (none on AH) but I plan on replacing IBF with it as threat is somewhat of an issue.
Thanks for the tips on my spec. I wasn't too sure where to put those 2 points I have in Chilblains.
Shouldn't I keep Acclimation though? I'd think it'd be a much needed talent for frost dks or do we just depend on Anti-magic shield?
I read a post some time ago about Acclimation that made a good point, that with Acclimation you're spending three points to get a "chance" to gain some protection, in limted fights; when those three points could be better spent picking up a talent that "will" give you something. I bought into the argument, and since getting rid of Acclimation, I have not missed it. That said, the points in there are not horrible by any means and I can understand it. I used to love Litchborne, even after it was nerfed, since it was a second way to get rid of fear effects, but then I had to look at the fights where i used it, and other then the Cat Lady, it really wasn't useful.
I use AMS for certain fights (Emalon and Brundiar in IC) and with DBM find that it's fine.
Best thing you can do is tank, and see what works for you. I've tweaked my spec numerous times and still don't know that I like the way it "feels."