(1) One of Hayek's most compelling arguments for the virtues of markets over government is that markets (via prices) reflect the constantly shifting preferences of millions of agents, and as such are both efficient and democratic. But the market for Collateralized Debt Obligations and Credit Default Swaps did not reflect the preferences of millions--they reflected the views of a very small number of people, some of whom had enormous market power (for awhile, anyway). A takeaway from the book is how large institutions could rig prices of over-the-counter investments for long enough periods to do substantial damage.
(2) While I loved the book, and will indeed use it in class, it may suffer a bit from ex-post thinking. The heroes of the book, Michael Burry, Steve Eisman, Greg Lippman, bet early and often against subprime mortgages, and made lots of money as a result. Ex post, their bets seem obvious, and perhaps ex ante, they should have seemed obvious. My strong suspicion is that Burry--who went to the bother of actually reading and analyzing offering circulars--really did know that he had a positive NPV bet ex ante. And loan originators surely knew they were underwriting junk, because documentation was so week. But perhaps not even Burry knew how big his pay-off would actually be.