Now, it's not a surpise to any of these groups (except perhaps the democratic forces) that this would happen after the revolution. The only surprising part is who, exactly, ends up against the wall. All of the groups plan on it being the other groups who are disposed of. I have no problem believing that the Ba'ath and Al Qaeda would form a common Caliphascist axis, cooperating while planning the swift and painful demise of the other as soon as they had smashed the current world power (the USA).
In fact,the religious factions of the Caliphascists may not consider the fall of Iraq to be all that much of a loss. It got rid of Saddam Hussein for them and if it ends up bogging down the US then that's all to the good. The bad outcome for the Caliphascists is a well ordered, properous Iraq. Leaving Saddam Hussein to the Coalition while preparing for guerilla war afterwards may well be their best strategy.