The contribution of mathematical models to the present crisis has been vastly overblown. The breast-beating and mea culpas from the likes of Derman and Wilmott are self-flattering: after all, if you caused the problem, you must be important! In reality, the quant is at the bottom of the pecking order on most trading floors. The people who trafficked in securitized garbage did so not because they were fooled by their models, but because they were paid to. You can't tell me that the guy who lent $750,000 to a strawberry picker with $14,000 income would have thought it a good idea if he was lending his own money.
Contrast this to LCTM, which really is an example of quants gone wrong: those guys had so much faith in their models that they not only put their own money in the game, they borrowed money to invest in themselves! They were doing the same things they had done at Salomon but they failed to appreciate the importance of being able to lean on Solly's balance sheet in times of trouble.
As for Taleb