Shield as of 1.2?

[DraconisOrion]

Ok, I was playing as our group's (PvE 90%) tank, using the Iron Fist build (I do some side PvP) and I am only level 48. We do well as a group (sniper, operative, and Sorcerer (healer)). I still have some issues with the 46+ level Heroics and FP (mostly on Multiple Elites, Champion/Bosses) in holding the aggro. I was thinking of going more to a 31pt Shield spec, are there any recommended builds and rotations post 1.2?

 

I do need to do some dmg to help out, but primary role is as tank, for this group at this level of play.

 

Thanks!!