So, unless you are super duper geared in ilvl 270 gear, you have probably noticed a bit of a drop in AOE threat. It took a bit of getting used to, but I have worked out a nice little rotation that seems to help with my Warrior.
Obviously this is nothing cutting edge and I am not what you would call a Theorycrafter, but I was doing some very decent DPS in Heroics. Obviously there are some new mechanics in effect.
Two of the most notable things to me are
a) Thunderclap sucks ass for AOE threat.
b)Rend is actually useful for once.
My new standard AOE rotation is.
Rend. Yes rend.
Thunderclap. Thunderclap will spread rend to all of the other target in range.
Shockwave. Shockwave hit harder after a Tunderclap.
Cleave when able.
Shield Slam when able.
Voila. Now you are AOE tanking like less of a noob.