I suspect that New Orleans is going to be just fine in the future. At least as well as it was before Hurricane Katrina. In terms of infrastructure, the US Army Corps of Engineers rebuilt the levees that were breached during the hurricane. And while a direct hit by another major storm would still be a disaster, people now have better ideas and expectations how to prepare for an event like this. In terms of economic recovery, the city actually seems to be doing surprisingly well. For example, the Super Bowl, the largest single sporting event in the US, was just held there earlier this year. Such an event in New Orleans would have been unthinkable in the years immediately following the hurricane. New Orleans is fortunate to not have an economy entirely based on a single industry (like Detroit). And New Orleans has a lot of business tied around an industry that cannot pick up and leave to go just anywhere: tourism. In 200 years, people will still be visiting New Orleans for the same reasons they do now: the food, the music, and the general atmosphere of the city.