I don't know. Those with big houses in the Uptown area are rich enough to go back. And they are tight with Nagin.
I would be surprised to see any business set up housekeeping in NO.
What was the attraction of New Orleans that lured the rich folk to want to live there? If the remnant of New Orleans is not viable enough to continue to provide night life and the other amenities that made living in NO enjoyable for the rich, they will leave too