"The most significant barrier to a housing market recovery: 301,414 homes for sale.
The number of homes available for sale across Australia has been decreasing; however stock levels remain well above average.
Over the four weeks to 8 July 2012 RP Data tracked 301,414 unique properties advertised for sale across the country. While the number of homes available for sale is very high, the volume has been reducing and is actually about -7.4% lower than when supply levels peaked last November. ... Clearly, the large number of homes available for sale is due to a lack of absorption rather than a large number of new listings being added to the market."
See Property Pulse.
There are also a large number of properties that owners want to sell, but cannot, so they have been withdrawn from the sale process and rented out, with the hope that the market improves.