The U.S. plan to drop 3,000 bombs and missiles in 48 hours is called “Shock and Awe”.
The idea is to so thoroughly confuse, frighten, and demoralize the Iraqi military that they will simply be unable to fight at all. Soldiers won’t get into tanks, command bunkers will be abandoned on fear that they will soon be hit, etc.
To make this all more likely, the first phase of the war is already underway - the psychological preparation. The U.S. is dropping leaflets over military positions telling local commanders that:
A) if they follow orders to launch weapons of mass destruction, they will be treated as war criminals. “Following orders” will not be allowed as an excuse.
B) The U.S. has no interest in punishing mid-level officers for past war crimes. The only people that will be held accountable will be Saddam and his inner circle.
C) Officers and enlisted men who surrender early will be given preferential treatment, and will be allowed to keep their jobs in a post-Saddam military.
D) If you’re job means staying in any recognizable military structure or vehicle, you might want to be AWOL when the war starts, 'cause we’re going to destroy it all.
and most importantly:
E) This time, Saddam is definitely going. There will be no half-measures, so you don’t have to worry about deserting and then facing Saddam’s wrath six weeks from now.
The thinking is that the Iraqi military itself has no love for Saddam, and the only thing that keeps them in line is fear of Saddam. So the U.S. will counter that by making sure that they fear the U.S. even more, but that the U.S. really wants to be friends with them and holds no grudge against anyone but Saddam.
In the meantime, by all reports there are already a lot of special forces in Iraq preparing to sever key communications lines, secure oil fields so Saddam can’t torch them, etc. If the last Gulf War is any guide, there are special forces waiting right now near critical installations. When the war starts, they’ll use laser illuminators on the ground to ‘paint’ targets for smart bombs. This will be done especially in areas where there are sensitive civilian targets nearby that the U.S. wants to make sure it doesn’t accidentally hit.
Of course, the real plan could look totally different. Disinformation is a standard tool in war.