The days of al Qaeda in Iraq having standing armies in cities are over. The days of them crucifying people on the stadium lights of Diyala are over. However, they will remain like the Ku Klux Klan did after the Civil War: ready to strike and kill at random.
The Mahdi Army and Katab Hezbollah are defeated. No longer do they enforce Islamic law on major cities. However, their sponsor Iran will go the Lebanon route and try to give their militant proxies veto power over the political process.
Saddam is gone. That mission is accomplished. The future though belongs to Iraq. Iraqis have the say on whether or not there will be peace... if outside radical Sunnis and revolutionary Shia let them.