I dont think anyone can declare multiculturalism a great success in such a short span of history. I think it will be another couple of generations, maybe another 50 to another hundred or more years before any big cracks will really open up and tear the country apart. It has only been about 250 years since the first fleet arrived.
Hardly a huge span of time. That was when the whites and aboriginies first tried to
share the country. Didnt work very well.