Here’s a satellite photo of New Orleans that provides enough detail to show exactly which areas have flooded. You can also sort of gauge how deep the flood waters are. The creepiest thing about the photo sort of transition from above water level to below water level and back again.
Also, in the photo you can see that the French Quarter is still mostly high and dry, although the western corner is flooded. You can also clearly see that the Superdome is surrounded by water. (If you find the Superdome on the map, the French Quarter is directly northeast a few blocks, just to the right of the flooded complex of buildings that have what looks like red tile roofs.)
Update: The before picture.