Iraq has claimed they will abide by the Geneva Convention on treatment of POW's. Soldiers in uniform are entitled to the protections of that treaty. That's where the familiar "name, rank and serial number" comes from. Apparently, parading them on TV is a violation, as is using them as shields.
The Guantanemo prisoners are not soldiers strickly speaking and thus not entitled to POW treatment. We could line them up and shoot them if we wanted. They are considered terrorists and fall into the same general category as spies, saboteurs and the Saddam fadeyem. The latter, who are distinguishing themselves by staging ambushes from hospitals, killing civilians and executing surrendering Iraqi soldiers, should in fact be executed upon capture as war criminals. No doubt some pacifists will object.