If you are thinking of coming to OZ and are in the construction industry, here is my honest view on the situation first hand.
This is based on Perth and Brisbane, But I understand Sydney and WA are the same
Painters: Lots and lots of painters out of work. ( If you want to know why this is I will tell you)
Ground workers: Nothing to start, unless you can find the odd swimming pool. No road work jobs either.
Roofers: No roofing jobs, May find the odd domestic roof, But up against a lot of other quotes.
Bricklayers: Very hard to find work, lucky if you get 2 days per week.
Carpenters: Very hard to find work, Lucky if you get 2 days per week.
All types of plasterers: Seems to be work at the moment, but will go the same way as bricklayers.
Plumbers: Work out there, but will need to retrain, could start to go tight tho.
Electricians: Work available, but will need to retrain.
Wall and floor tillers: The best trade for finding work, seems too be plenty going on due too domestic work.