Warrior AoE tanking in Wrath

Here's how I usually do my AoE tanking for a pull consisting of 3-5 mobs:

Mark skull, X. Charge skull, Thunder Clap, Shield Slam skull, back up a couple of steps, Shockwave the pack, tab target to X, Revenge X, tab to 3rd mob, Concussion Blow, Thunder Clap, Shield Slam skull, Revenge 4th mob (if any), and all the while spamming Cleave.

Assuming you have Warbringer, 2/2 Damage Shield, and a decent Block Value, you should have no problems holding a pack of 4 mobs. A pack of 5 tends to be too hectic, and a pack of 6 (elites with high HP) will border on mildly uncontrollable. 7 would be quite unmanageable.

Oh and as previously mentioned, if you have Greatness, use it to tank. It works wonders.