Baghdad seems like "a city too far" as an H-hour objective. There are too many locations that need to be hit in and around the city, with force protection being the top priority. Saddam could sucker 100,000 troops into Baghdad, then order his commandos to blow damns on the Euphrates. And I doubt he'll be able to launch SCUD missiles from within the city.
In addition, I question whether or not we can land, then support such a large force early on. Baghdad's ADA will shred helicopters, and low flying cargo planes. Downed aircraft will cost us the momentum, dramatically shifting how the operation is conducted.
The closer the people is to their leader, the more determined they'll fight. Baghdad is the one city Saddam controls without a shadow of a doubt. The people and soldiers will resist because of fear, loyality, and hatred for the West.
We all know what Saddam will likely do given the press reporting. Convinced Baghdad is the primary OBJ at H-hour, he'll order all RGFC to move toward the city to defend and repel the light air assault force.
It's better to make Saddam think we are going to take Baghdad early on. He'll move his Center of Gravity, the RGFC, to defeat us. Then our forces can assault seizing most of country rapidly, likely capturing many of his WMDs. The less space Saddam has to launch SCUDs, the better. He'll most likely try to preserve his missiles and launchers by moving them closer to the city as well. Our planes can then hunt them down more easily in the small area.
Capturing Baghdad will be an difficult task under any circumstances. If we try to take it at H-hour, the light force might be seriously mauled, cutting back on our combat power, boosting enemy morale, and contributing to a slower advance. Even if we capture the city, holding it until link-up will be a difficult.
I say let Saddam think Baghdad is the primary OBJ. While he's trying to defend the city, we take the country from him. Then all our forces, as can concentrate on a single point. Airpower can attack artillery, reducing, although not eliminating, the threat of WMDs, and we will have the force to defeat the RGFC for good.
Urabn terrain doesn't favor anyone really. The Iraqi's already have trouble coordinating. The ubran environment will make this worse. Troops will find themselves cut-off, or feeling cut-off and abandoned. This will make success more likely for us.
However, we must assume the enemy will fight like hell. People should prepare for massive casualties, then pray a bloodbath doesn't materialize. More importantly, we're gonna have to accept the horrible truth of urban combat. Innocent people will die. Neighborhoods will be reduced to rubble, etc. That's war. The US and it's allies can't assign unreasonable ROEs to commanders to appease international governments who, if were fighting in the same conditions, would level the city before sending in troops.