I'm still pulling for Iraq. This was almost certainly an Al Qaeda attack. The partisan politicos who are hopeful to see their dire predictions born out are secretely satisfied to see trouble in Iraq, but they underestimate Iraqis and they're oblivious to the fact that most Iraqis are capable of putting two and two together.
If the government and various religious leaders can hold together after this bombing of the holy shrine, Iraq will be able to weather anything Al Qaeda throws at them. Long live Iraq.