New Orleans is ready to evacuate and they are doing a lot more than they did with Katrina. They have said there will be NO shelters within the city and they have a whole program to get people out who need assistance, don't have transportation, etc. They have moved food and water into Louisiana already. Seems like they did, indeed, learn from their mistakes so hopefully, even if the levees don't hold, there won't be loss of life. I read an article trying to analyze whether the levees are ready for this and the gist of was that they are NOT ready.
ETA: Some evacuations are actually beginning. This website has details:
http://www.nola.com/