The real battle, folks, is yet to begin!

Who Are Saddam's Most Loyal Forces?

Republican Guard
60,000-100,000
Controlled by Saddam's younger son and heir, Qusay, the Guard includes three divisions deployed around Baghdad and one near Saddam's hometown of Tikrit. Guard forces crushed a Shi'ite uprising in Basra in 1991. Though the Guard's heavy weaponry is outdated, U.S. officials believe Saddam may have deployed chemical weapons to the Medina Division.

Special Republican Guard
15,000-25,000
Largely recruited from Saddam's al-Bu Nasir tribe and other loyal groups, SRG troops are scattered throughout Baghdad and well-trained in urban combat. Its units protect Saddam and top Baath Party officials.

Fedayeen Saddam ("Saddam's Men of Sacrifice")
20,000-25,000
Formed in 1995, the fedayeen handpicks members as teenagers from loyal tribal areas and are considered among the fiercest of Saddam's fighters. Often disguised in civilian garb, fedayeen units have mounted attacks against coalition troops. Operating outside the law, the group has a "death squadron" that executes people in their homes

Al Quds (Jerusalem) Army
Size unknown
A volunteer civilian group, the Quds militia was founded by Saddam in September 2000 with the supposed purpose of "liberating Palestine." Now providing domestic defense, Quds fighters (which include women) are trained in basic combat. They have staged guerrilla attacks outside Baghdad, then faded into residential areas when pursued

Secret Police and Spies
15,000-25,000
Saddam has eight overlapping security agencies. These include layers of domestic and foreign spies, guerrilla operatives and "enforcers" who intimidate Iraqis to fight. Qusay leads the most powerful agencies, and members may have access to chemical or biological weapons. The U.S. believes more than 300 agents are working abroad under diplomatic cover
[from the April 7, 2003 issue of the TIME magazine]

And I'm sure the Allies will face a tough resistance from these forces. They are highly motivated and loyal to Saddam, unlike the rabble that is the regulation Iraqi army. Moreover, these forces will fight to the last man and probably use the civilians as shields, making it a tough urban battle in the Baghdad streets. Here, the air-superiority of the Coalition forces will not mean much, unless they are ready for huge (and I mean, huge!!) collateral damages.

Testing times, for sure!