The number you DON'T see---and it's almost impossible to find---is the number of terrorist/"insurgents" being killed. These people are being destroyed at UNSUPPORTABLE rates. There is no military operation---guerilla or otherwise---in history, no matter how well supported from the outside, that has sustained the levels of losses that the terrorists in Iraq have and not collapsed. The math is unrelenting. Even the Japanese ran out of voluntary kamikazes.
I don't know where you are getting your information from re the number of enemy casualties, but I don't buy the body count metric. We tried that in Vietnam. If Iran and Syria keep on sending people in, there will still be a level of conflict and insurgency. If we can dry up the water the guerrillas swim in, the insurgency will die. It took the British 12 years in Malaysia. We need patience and perseverance.
AND, Iraq's new government hanged 13 of the SOB's this morning. May it hang many more.