Besides releiving atmospheric pressure and redistributing moisture.....
Hurricane Katrina in one way has re-directed Bush's plan to bomb and invade Iran. All those troops and supplies and man-power hours have now been re-directed to our Gulf states............where they belong.
To this extent, it will slow (if not completely halt) this administrations's plan to a) remove dictators b) find weapons of mass destruction c) bring democracy to a totally different culture d) rebuild THEIR cities and e) further their quest for world domination.
Does nature itself has it's own sets of checks and balances?