Go! I just got back from a great weekend in NOLA for Southern Decadence. It was one of the largest events held since Katrina and businesses throughout the Quarter def made us all feel welcomed.
I saw some devastated areas between the airport and the city, but the Quarter is open and ready for you to visit. The housing shortage has created a labor shortage, so be patient if it takes a couple of minutes longer for your (overworked) waiter to get your food to you.
Just as important as the physical rebuilding that is slowly taking place is the economic rebuilding that is also steadily progressing. Visit the city, have a great time, get served by some very grateful people, and help them rebuild their economy. Everybody benefits. ^