There are certainly things that could assist Perth turning around in the future.
Farming was mentioned above. This could assist Perth but will take a while if it does. There are large corps and governments either are or looking at buying up big parcels of farming land. You would think this would drive people to stay or move into regional areas but if it heads like US farming, large corps run nearly all of it. They use less people and more mechanical equipment so people in these areas would head to the cities for work.
Lots of people who live in mining regions are also heading back to Perth, albeit some may return to other states as well. These both will assist sustaining the Perth market but I couldn't give you any figures on how much.
Perth has some fantastic things to offer, lifestyle, beaches, (although a Shark Watching Business could be a good opportunity lol), weather, wine region, Swan River, just to name a few and a great stadium as well as things like Elizabeth Key etc . Cost of living is very high though, beer and food/eating out is ridiculous IMO.
The state government are also in the process of releasing a large amount of state owned land to raise $ to pay back their spending of late. This could have a negative affect on pricing.
It's a hard guess at the moment, lots to factor in. I personally feel Perth will take a hit over the next 12-24 months at least before any sign of an upswing.
