The problem I see with your argument is that, although security should improve over the next 3-6 months under current conditions, delaying the election may (would) embolden the insurgeants.
I think they are emboldened already - it comes down to whether we can kill enough of them, and break up the organizations significantly enough before the election (whenever it is) - to prevent mass slaughter at the polling places. can we? are the iraqi forces and the police up to it, or do they need more time?
Fallujah didn't go as we expected, we have to face that. The weeks and weeks of advance notice, leaflets, warnings - and then we act surprised that a good number of the insurgents simply relocated someplace else and continue the fight.
the scenario that scares me is this - right now, US public support for this iraq effort is in the low 50s. if we have this election, and its a mess, and it leads to civil war, the media is going to go nuts with their coverage, and US public support is going to drop into the low 40s/high 30s. Rumsfeld is hanging by a thread right now, what do you think is going to happen to him in light of that? so then we have this new iraqi government in place, its now up to them to fight the civil war. are they up to it? are their security forces going to go in there, house to house like our Marines are doing, and root these guys out? I don't see any evidence that the iraqi police are up to it. and how long is US public support going to hold up, how long will this be sustainable? what happens if we lose Rumsfeld? if this iraq effort implodes, its the last time you will ever see the US use the military in a pre-emptive strike like this (this is what the Dems and the liberal MSM really want, they want us neutered).
are all these risks worth it, to stick to the 1/30 date? that's the question we have to ask.