The most likely weak link for a catastrophic breach is actually the west side levee, which is the lowest at 10'. Because the topside winds have been blowing to the west and then southwest before eventually coming out of the north, all that water blown in the lake are first pushed towards the spillway to the SW of the lake, and the first danger is that builds up so much as to overtop the west side. Now as the eye moves even to the city on the east side, the worst danger area expands to the city's north shore, as the winds max and shift to coming straight out of the north.
Also people may not realize that there are levees separating the main area of NO and the city's northeast side, the closest side to the eye. So it is possible that one could see catastrophic flooding while the other does not. Time will tell.
Thanks for providing the details. I don't actually think we'll see major breaching, but my point was broader...that the situation will just be worse for future storms unless changes are made.