I predict that QR will deploy their A380 to Melbourne in the next 12-18 months.
This is not based on anything I have heard, but rather my personal analysis of the Australian aviation market and QR's need for competition with EK and EY.
Now that they have SYD slots, won't it get upgraded to an A380 before MEL? As a member of OW they would get lots of feed from QF onto their late evening flight (as QF1 SYD-DXB leaves around 4.30pm), whereas in MEL they have a similar departure time to QF9.