Canberra Airport is planning a high speed rail terminal to quickly transfer passenger to Sydney (Airport willing to fund rail terminal, ABC News, ). The incorporation of freight could make a Sydney, Canberra, Melbourne high speed train service more viable, with freight moved from aircraft to train at the same time the passengers are boarding.
In March Euro Carex ran a high speed test freight train from Lyon to London. The train is actually a modified TGV passenger train used by the French post office for carrying mail. The consortium plans to run dedicated high speed freight trains between European airports to transport freight at lower cost than possible by air. Dedicated freight terminals will be built inside the security perimeter of the airports, allowing container to be moved securely between planes and trains.
Australia would not have enough freight to justify dedicated trains. Instead I suggest dual mode trains be used with passengers and freight. The freight area would be separated from the passenger compartment for security. On high capacity routes a modified double deck train could be used, with the freight on the deck above the passengers. A separate secure upper platform would be used to load freight at the same time passengers are embarking below. The same roll-on and roll off systems as used for aircraft could be used to load the trains and both road transport pallets and air containers could be used.