But if you have a smattering of economics background, my opinion, uninformed by a lot of economic knowledge, is that it is a very informative and interesting book. Whatever else you can say about the guy, he's smart and he's well informed. I've probably mentioned that he's won the Nobel prize for economics, specifically I believe his macroeconomic work, with which this book was loaded. A few of the factoids I picked up are that 1) we're in an economic situation when "the normal rules do not apply" and if we don't realize it we're going to get in a lot of trouble, 2) situations like this have arisen before, not just in the Great Depression but also in Asia in the 1990s, Mexico, and other areas, and 3) that a "tight" fiscal policy at this point could be disastrous (such as an insistence that spending rates be sharply curtailed - thinking like that was partly responsible for the depression).
One of the interesting facts discussed was the "shadow banking system" that has arisen in recent decades. This is a system of credit that performs functions that used to be performed by consumer banks but that evolved to perform them cheaper and better. It includes things like the auction-rate security system. These parts of the shadow banking system were profitable because they were not regulated by the Federal Reserve system, which let them operate with less capital on hand and also take much larger risks. As long as nothing goes wrong, this works great and everybody makes money. But if something does go wrong then 1) the system is very vulnerable to problems because it takes big unregulated risks, 2) it cannot be directly bailed out by the Federal Reserve because it is not a normal bank so is not ensured by FDIC and so 3) you can have "runs" on this system just like they used to have runs on banks prior to the establishment of the FCC. This shadow banking system took a huge hit when the housing bubble burst, and was a huge source of credit that essentially dried up. That actually helps explain why TARP had such limited effects on credit - the deposit banks that are regulated by the Reserve were not the only, or even the major, sources of credit. The "shadow banking system" got no TARP funds and is still not lending. An obvious implication, pointed out by Krugman, is that anything that performs the functions of a bank, including this shadow system, should be regulated like a bank - to avoid exactly this sort of thing happening. This is not stuff I've seen covered in the news!
So, if you're up for a little work, I'd recommend Krugman's little book. It's not as fun as Freakanomics, but it's just as fact filled, and probably, sadly, more pertinent.