Walkinshaw (owners of HSV) currently convert the Dodge Ram to RHD. That involves moulding a new dash, new steering box and cutting and shutting the floor pan. They are capable of doing the same to the Camaro.
I think from what I have read, Holden and HSV have been surprised (if not caught off-guard) by how the Mustang has succeeded. It is factory built in RHD of course, so it's going to be a cheaper car. It shows that no matter what the greenies say though, Australians want a V8 car.