Gnadenburg, agree that prime inner city areas are some of the last affected, but if more land is released quicker in the burbs, this has an overall effect on supply and demand, with more people moving out to more affordable areas, general demand softening and prices therefore also developing to a more sustainable level.
IMHO, this is what this country sorely needs. As a property owner, you are naturally resistant to any school of thought arguing for lower overall property values, but 7.5 times average income is not sustainable, and in conjunction with the widespread availability of easy credit for everyone it's outright dangerous as masses of average income earners overextend themselves, and when credit availability contracts, lots of people are in trouble. You can watch the beginnings happening at the moment, in the US it's in full swing..