It keeps shifting west. It may not threaten NO at all when it makes landfall. No one knows. It is still not at hurricane strength as I write this...it needs to slow and strengthen considerably to be a real threat.
That said, NO is still below sea level last time I checked and even a wimpy hurricane would be a problem if it made a direct hit on the city.
But it's also moving fast and that would mean a short duration over the city if it did hit there.
Thankfully, there is a new mayor (yet another in a very, very long line of congenitally corrupt Landrieus) and a Republican governor this time around so I would expect a much better disaster management scenario. Plus a lot of stupid people died last time and quite of few of the surviving stupid people were shipped out of town and never came back. I also imagine that there are a lot more firearms in the hands of the citizens so that should be better this time around...i.e., the shop owners can better shoot the cops who attempt to loot the stores.