Do you know about the "minor" Glyph of Intimidating Shout?
Nope? Well neither did I.
Old time players have a love/hate relationship with Intimidating Shout--it was great back in LBRS--because it could buy your party the time it needed to kill some nasty pull. Unfortunately, using intimidating should was much like throwing a large rock into a pond. A sure as the tide, mobs frightened away would come surging back most of the time with friends.
In the cramped and tightly packed dungons before Cata, while a well time Intimidating Shout might buy a few precious seconds to kill some hard target, it almost always ended in a wipe.
Cata has enough room that there are at least a couple of places where Intimidating Shout can be used and send mobs scurrying.
Glyph it, though, and prot warriors can worry a whole lot less about the effectiveness of their CCers--any party can burn down a lot of mob in the duration of charge, shock wave and intimidating shout.
I haven't tried IS as a DPSer, yet. I know that fear traditionally generats a ton of agro so IS could keep a DPSing warrior uncomfortably high on a number of agro tables, but glyphed it can go along way to help "solve" the problem of warrior CC.