If nothing else, Katrina has taught us that a vacationing President is a worthless President. Two huge disasters have befallen this country while Dubya was playing cowboy (not so stunning when you have a leader on vacation more often than Robin Leach.)
Both times, Bush was caught with his pants down (to the delight of Turdblossom.) This may be shocking to say, but it turns out less work gets done when our elected leaders are not working.
Worst President Ever.