I ran across an interesting an article which led me to a series of panel discussions on real estate that are posted on YouTube.
Here is a link to some great reading.
http://knowledge.wharton.upenn.edu/category.cfm?cid=8
Here is a link to the interview with Sam Zell. He talks about what makes this downturn in real estate different from previous downturns. I find the “answer” to declining values at the end of the clip to be very insightful.