From the release notes:
Karmic Strike's finisher no longer leaves a monk helpless. The effect has been changed to, "Fire-Dark-Fire Finisher - You have learned to strike at the moment your opponent is the most vulnerable - the same moment your opponent strikes you. This attack is guaranteed to produce critical threat if it hits, but costs 20 hit points to perform."
Actually Karmic Strike still makes you helpless. I've made a short vid to demonstrate it:
http://www.youtube.com/watch?v=Gs3xmpIHWxQ