I'm a tank, and I've seen some amazing things coming out of arms warriors lately. Specifically, very well timed Throwdowns, as well as stance changes to disarm, and liberal use of Intimidating Shout.
Warriors have actually been pretty good at preventing damage taken on me. Sometimes I even assign a DPS warrior to tank a caster if we haven't got enough CC. They seem to be able to keep casters more than busy without taking much damage themselves.
To anyone who thinks warriors are inferior to a ranged DPS, I don't think that it's the case.