Seems to be one of those skills that is mostly situational. I don't find myself using it all the time, but I can say it has saved some fights for me using it at the right time.
Example:
Turn Order is You, Enemy, Healer
All your skilled but Provoke are on cooldown. Unless you get a lucky critical hit, the enemy will get to kill your healer if you don't CC him.
Now this is very situational, but this seems to be where Provoke shines the most.... when you got nothing else to use. :P
