The residential market's "shadow inventory" is up more than 10 percent from a year ago, according to real-estate research firm CoreLogic .
That puts overall inventory at more than 6.3 million unsold homes on the market, nearly a third of which are "pending supply" -- those homes that are seriously delinquent, in foreclosure or being held off the market by banks or other investors.
CoreLogic  has more:
According to CoreLogic, the visible supply of unsold inventory was 4.2 million units in August 2010, the same as the previous year. The visible inventory measures the unsold inventory of new and existing homes that were on the market. The visible months’ supply increased to 15 months in August, up from 11 months a year earlier due to the decline in sales during the last few months.
The total visible and shadow inventory was 6.3 million units in August, up from 6.1 million a year ago. The total months’ supply of unsold homes was 23 months in August, up from 17 months a year ago. Although it can vary and it depends on the market and real estate cycle, typically a reading of six to seven months is considered normal so the current total months’ supply is roughly three times the normal rate.