No, the 2008 crash wasn't a black swan. It just came from the debt side, rather than the equity side. It was clear this was coming. In 2004, I wrote this, on my "downside.com": [1]
The next crash looks to be housing-related. Fannie Mae is in trouble. But not because of their accounting irregularities. The problem is more fundamental. They borrow short, lend long, and paper over the resulting interest rate risk with derivatives. In a credit crunch, the counterparties will be squeezed hard. The numbers are huge. And there's no public record of who those counterparties are.
Derivatives allow the creation of securities with a low probability of loss coupled with a very high but unlikely loss. When unlikely events are uncorrected (I meant uncorrelated), as with domestic fire insurance, this is a viable model. When unlikely events are correlated, as with interest rate risk, everything breaks at once. Remember "portfolio insurance"? Same problem.
Mortgage financing is so tied to public policy that predictions based on fundamentals are not possible. All we can do is to point out that huge stresses are accumulating in that sector. At some point, as interest rates increase, something will break in a big way. The result may look like the 1980s S&L debacle.
It took longer than I expected for that to kick in, but it happened.
[1] http://downside.com/news.html#comingmortgagecrunch