Harith al-Dhari, the leader of the Muslim Scholars Association, gave an interview to Al Jazeera (from exile in Amman), in which he attacked Iran for its "cancerous" influence in Iraq. But, interestingly, he didn't include Sadr's Mahdi Army in the list of Iranian-backed groups:

Iran's influence is cancerous. It meddles in every aspect of life in Iraq. Its influence on Iraq's ruling parties is not a secret. The Al-Daawa party of al-Maliki, the Islamic Supreme Council of Iraq [headed by Abd al-Aziz al-Hakim], and Iraqi Kurdish parties are ruling parties and all of them were either funded by or established in Iran.

These parties are the pillars of a government formed under the occupation, so if the occupation goes all its allies will go with it.

Iran nowadays has the upper hand in determining who rules Iraq. Economically, Iranian goods have been flooding Iraqi markets. We have documented evidence that the Iranian Revolutionary Guards are working actively in Iraq through their Jaish al-Quds (The Army of Jerusalem) militia. Senior officers of the militia are based in the offices of pro-Iranian political parties.

I've never heard of the Army of Jerusalem, by the way.

Dhari says that the Iraqi resistance is holding off rather than engaging the Awakening movement of Sunni tribes who are cooperating with the United States:

I think the resistance has chosen to back off and not engage al-Sahwa militias to avoid internicine fighting. They are regrouping now and for sure will bounce back.