if prices don't come off 40%, it'll be a first, page-25

Personally I'm always wary of stating my opinion as fact, and I'd certainly never say 'never'.
I believe you will be absolutely gobsmacked at how quickly prices fall away, perhaps particularly in Melbourne.
Sentiment has definitely turned, and with some justification. Marked supply imbalances are now presenting themselves at just the wrong time (reduced demand, credit tightening, higher lending costs, uniform overvaluation vs long-term trend, decreased affordability etc).
I am genuinely surprised that relentless price appreciation (most recently at previously unseen levels) can be considered the norm, whereas any return to more realistic valuations is deemed to be impossible.
On the contrary, in my opinion such a development would be totally unsurprising, reflecting nothing more than the traditional rise and fall of a market.