Wrath Spec'd Warrior Priests can dish out good damage. See pics like this before with them. I have been #3 in damage, #1 in healing and #1 in killing blows before. Most of the time a well played BW or Sorc, usually blows me away.
I went Grace spec, which is nice for single target heals and debuffs and buffs. At level 21 I do pretty good.