From the October Issue of CGW: These guys are different from tradition clerics, typically chainmail-wearing badasses that heal. Priests can only wear cloth armor, but their spells are based on messing with your targets mind. Besides being the best Healer and buffer in the game, the other priest powers (into either Shadow or Holy magic) make him seem more like an inquisitor than a medicine cabinet. Priests use Shadow/Holy Words, wich are instant-cast and include : Dominate (make your enemy become our pet), Confusion (stops attacking), and Fumble (causes your opponent to miss). Armor: Cloth only

When casting, spells being cast are not interrupted unless the attack is specifically designed to interrupt the spells. However, if the priest is hit while casting, a spell will be delayed.

Priests get Mind Control spells that allow the priest to control their enemies.
Mesmerize allows the priest to entrance one enemy. They cannot Mesmerize more than one enemy at a time.
Dominate allows the priest to ?take control? of an enemy. He essentially possesses the body and has all that creatures abilities available to him. The drawback is that he suffers the inability to control his own body while dominating.

Holy Magic appears to be a line of healing spells for the priest.
Shadow Magic gives the priest the ability to do direct damage and damage over time spells.
Holy Word Shield will allow the priest to channel magic through melee and cast spells without delays.
Priest can also Resurrect other players, and has Sight abilities which allow the priest to see distances up close and scout out areas to some degree.