I'm sure major changes will come out of this. The Loma Prieta earthquake resulted in the relocation of highways, the reinforcement of housing built on land fill, and a number of other measures that have made SF/Oakland much less vulnerable.
Katrina will probably result in many places being declared off-limits for housing (as along the Mississippi flood plain), a massive rebuilding project, and possibly a system of dikes or flood barriers. If nothing else, the port is too important to abandon. It will involve Federal money and work, but in this case, I think it's called for.
For one thing, NO - well, all of LA - is so corrupt that maybe getting the mitts of the local politicians off of the rebuilding effort would be a good thing. Not that this would prevent corruption, but it might make it a little harder and maybe a little more actual work on the problem at hand would get done.
Read- more of our tax dollars wasted on a lost cause
Earthquakes can also come as a result of the pressure of flood water weight. New Madrid is too close for comfort.