Really, it's unknown. I'd like to say otherwise, but nobody knows, unless the designer is still alive and will post to FR.
However, I think the chances are pretty good that the SuperDome will survive more or less intact. It was a monumental-class structure designed in the Cold War/Civil Defense era. Despite all the disclaimers about it not being intended as a shelter, I would not be surprised if the architects didn't have that exact usage in mind as a secondary or tertiary usage. I'm really not at all worried about the structure standing up to the winds.
What I *am* worried about is the prospect of a nearby tall building falling on it (possible, unlikely) or floodwaters undermining the foundation (possible, I don't know how likely this is an issue).
As for it being a deathtrap - if you're stuck in NO and can't get out, the SuperDome is by far the strongest building in NO. It's the best shot people have, IMHO.
I watched it being built from my 12th floor dorm room window at Loyola University. It was neat seeing the lights of the city at dusk through the steel structure.
The Superdome concern is not in the vault-like protection failing. It is in the contained tens of thousands of unpredictable folks, and all their needs and weaknesses. There will be many stories to be told of that experience.