Apparently Dwarf Priests have very important skills in raiding. I remember my old guild saying something about needing more of them. :/
Yep, as MM said, Fear Ward. Horde do without it, though! Tremor totems seem to me like they'd be much more difficult to work with.
Ah, yeah, I remember we were running Baron and our priest kept casting that. It never hit my mind that it was a dwarf though, and I didn't remember that they had different skills.
Personally I think that Desperate Prayer is a nifty tool, especially when overestimating yourself in PvP, or when saving a raid, but some people may think otherwise.