Thanks to a couple of readers for suggesting this link. This sentence caught my attention:
"The market for RPX forwards does not seem to reflect the strength observed in the housing markets. Forward prices imply a 23% decline in the 25-MSA RPX Composite by the end of 2009."
I don't know anything about the details of the RPX market operations, but it seems that it is cheaper to buy a house via RPX than to purchase an actual house.