Sydney's housing prices are falling down, falling down, falling down, page-33

I think you should expect it and a different version.
That's what happens with all cycles, they peak and correct. The depth and speed of the correction depends on the height and momentum of the peak.
The prices aren't driven by the economy as much as by the positive emotions of the buyers and sellers as they feed the gravy train. When fear gradually replaces that euphoria nature will take it's course.