I still believe that this is one of the great things about setting up a democracy in a culture with Islamic subtexts like Iraq. Islamic radicals like this one permeate much of the Islamic world. In other states, these maniacs are dealt with "quietly." This allows the Islamic world to save face.
These public attacks in the name of Islam create an insufferable paradox for observers. How can muslims kill muslims? Skeptics of any stripe prosper from this paradox. Muslims have no practical alternative but to moderate.
I suspect their are many more waves of this maniacal nonsense to be endured in Iraq, but I still believe they serve our long term strategic interests by turning observing publics against such Islamic practice. Secular politics gains adherents.
The risk of Iraq becoming an Iran seems to diminish daily with every absurd performance of these fanatics. I suspect this is a factor in why Sadr is deciding to take three or four steps back from confronting the Coalition.
Unexpected Iraq bloodbath raises concerns (Shiite on Shiite violence as if it's new)