A good read: http://www.fool.com/investing/general/2011/01/28/financial-crisis-the-greatest-hits.aspx
I think people "inside the beltway" certainly knew of the probable collapse of the housing market. Hell, they helped to create the mess.
Give me a break. I work in a tangential field and EVERYONE knew it was a ticking time bomb. The reason it happened was that you could keep kicking the can down the road from the borrower to the bank to the GSEs to the rating agencies to the investment banks to the insurance companies to the investors. No one cared, because everyone got a piece.