I don't want to be too much of a Monday morning QB, but this sure is a missed opportunity:
The city declared a mandatory evacuation. Why then did it stick tens of thousands in the Superdome, right in the middle of town, rather than evacuate them with the assets they already owned in quantity?
Some critics are calling it a racist plot. If we rely on Coyote's Law, the most likely answer is incompetence and stupidity.
Update: Junk Yard Blog has extensive reports on unused busses, including more sattelite imagery, local evac plans, reports from locals, etc. Just keep scrolling down the page