I actually find the warrior superior to a pala tank.
But then again, i dont run the holy trinity setup, i have all 4 shammies elemental.
And 1LHW in aoe aggro is nothing, the warrior has no problem keeping the mobs on him.
With a descently geared warrior 6mob heroic pulls is no problem.
Thunderclap might only hit 4, but 1 is dead befor the tank takes damage, and the second is dead before the tank needs heal.
A pally lets me use chain lightning, but pally tanks in general take more damage, wich in turn lowers my dps.
A warrior also has a few "oh shit buttons" wich helps too.
Solo target threat is also supperior in my experience.

As for a more diplomatic aproach: The tank you are used to, is the best tank anyhow ;)