It's one of the principles of warfare, Sun-zu wrote about.
Deception in an attack.
You make it look like one thing, then do something completely different.
So the government tells the reporters up to now that it will be one hell of a bang all at once in a huge blitzkrieg, "That will shock and awe the enemy into surrender."
Maybe it will, but after 24 hours of "war" it has been anything but. I've seen one small raid on Bagdad to try and kill Saddam himself, and some a small town captured on the coastline.
The moral of the story is, don't be so gullible. The government and military commanders absolutely do NOT want you to have a clue about what the real plan is. It seems most news networks bought right into it.
Shock and Awe could come latter, or never. We'll talk about the real plan's specific details latter, say in about five years.