China only just released a new maglev capable of 600kph, that's Melbourne-Sydney in around 2 hours, which considering it would be walk on/off each end like a commuter train would kill aviation on the route.
That will all depend if it is subsidised by the government or not. Rail is uncompetitive with aviation if it is run as a real business like aviation where the customer is paying the full economic price of the ticket. The cost of a ticket on a high speed train would be eye watering if the customer paid the real economic price. For some reason however railways seem to get a free pass in this area. The same people who advocate railways always want the government to pony up regardless of cost or efficiency. High speed rail in Australia is just another white elephant which gets a free pass on economic and environmental grounds. I have never understood why it is always pushed along as some sort of solution when it is quite obviously not.
Bonzas biggest worry will be airport access not High Speed Rail.