Here is a long, but good, analysis of why the US housing bubble has burst more severely than the housing bubbles in other countries, some of whom had much bigger increases in home prices than we did.
One lesson that must be learned from the current crisis is whether and how we'll have to change the regulation of our mortgage market. If you're interested in that issue, this paper is worthwhile reading.
http://www.bis.org/publ/work259.pdf?noframes=1