The current debacle has taught the folks in the financial sector a very valuable lesson. They've played with fire and, while we've all been singed to various degrees, they themselves are the ones with the third-degree burns.
The pessimistic view:
When the hell has anyone in the financial sector ever learned a lesson from his past mistakes? MBAs or no MBAs, they exibit all the psychological charcteristics of habitual gamblers. They'll forget about their losses just as soon as they see the next opportunity for a big score, no matter how risky.
I think we should hope they've learned a lesson, but regulate the hell out of 'em just in case they haven't.