I found this article on subprime lending interesting. It defines a lot of the terms that we hear. Note that the link at the bottom of the article discloses his relationship with the lending industry. There are also more definitions there.
In a different news article on subprime, AIG has agreed with regulators to talk to their clients regarding the loans they received from the bank. Washington Mutual has already had a similar conversation with the Feds. Also in the article:
Earlier this week, Federal Reserve Board Chairman Ben Bernanke said the Fed will meet with mortgage lenders and consumer advocates on Thursday to discuss whether so-called low-doc or no-doc loans marketed to subprime borrowers should be prohibited.
The changes in the subprime market have not done away with below 20% down financing. The restrictions (lender imposed) on them have made them less common.