The biggest problem with trying to compare the Iraq War to World War II is that the two wars are not alike at all in respect to the cual fighting.
World War II was essentially a traditional ground and naval war, where success could be measured by the acquiring of territory and the confiscating ofthe enemies' resources (e.g. cutting off Japan from oil).
After the conquest phase of the war, the occupation phase was relatively peaceful. Yes, there were a lot of problems, but we weren't getting Americans shot and killed by insurgents.
Iraq, on the other hand, had a quick and relatively painles conquest phase, and is now essentially a war of attrition against an occupying power.
The way, in my opinion, to measure progress is essentially by measuring how much damage the insurgents can do to us vs. how many resources we can bring to bear against them. Or to put things another way, the success or failure of the war can only be measured by looking at the death toll/injury toll for the coalition, or by looking at whether or not we have the resources to continue. If the monthly death toll is getting higher or if we are running out of resources, we are losing.
Enemy body counts are mostly irrelevant, as we do not have an insurgency of a defined and finite size. Unless the insurgency shows signs of waning (i.e. decreased attacks), I don't think that body counts mean much.
Body counts reflecting the deaths and injuries on the coalition side do matter, though. Because we have a central structure which can be bled. Or put another way, we could eventually run out of soldiers or suffer so much damage that we have to withdraw. The insurgency does not have a central command which decides when they can no longer keep up the fighting.
So what options do we have?
(1) More of the same. This will probably lead to higher and higher monthly body counts, and eventually the recruiting problems will come to a head and we'll have to reduce troop levels or find some way to bring in extra soldiers.
(2) Withdrawal. One way or another, we'll have to reduce troop levels with the goal of getting out of Iraq.
(3) Escalation. We could decide to put more soldiers in Iraq, either by shutting down all our other bases, increasing recruiting or starting a draft.
(4) Brutal put-down. We could maintain or reduce troop levels, and simply bring order by mass murder. This is an option Michael Savage discusses often, where we bomb the Sunni triangle relentlessly. In essence, the idea involves responding to any attack on American troops by killing large numbers of Iraqis (probably Sunni Arabs). I there is difficulty getting security in the "Green Zone," all buildings around the zone will be razed and any Iraqi getting within, say, 500 feet will be killed.
Which method is most likely to be used? I'd say number 4.
That is all.