If Saddam really wanted to toss a curve to GW, he would leave and hand over power to his younger son. This would put GW in a bad situation to continue his campaign and the Saddam plan could continue ontrack. If you remember correctly, GW and the adminstration simply said that Saddam has to go.
I thought the stipulation was a full regime change. I do not think that the curnet administration would accept his son taking over.