Daily Kos has posted a daily security bulletin (distributed to civilians, not military) which paints a pretty scary picture. One of his commentators likens it to "the weather report for Hell and its suburbs"...
And for more scariness, check out this map (courtesy of Juan Cole):
The red areas are those where the US is completely unable to provide any sort of security. The purple areas are those where there has been recent heavy fighting. The white areas are "peaceful" - though given that Baghdad is classified as such, it's a rather generous definition of "peace".
Half the country is effectively in rebel hands. And the US think they can win this?