I'm not big into the numbers game, but I seem to do okay with my dual weild frost tank. I am not geared 100% but can handle ICC rep runs as a main tank and 10/25's as an OT with a good healer. Quick reference, my addon GS is only around 5120 and my wowheroes is around 2830. If you're close to that you "should" be okay to take on most stuff.
