Mafia 2 and 3 Definitives are available now. Mafia 1 Definitive on August 28.
Coolio, my Mafia 3 had been upgraded to "definitive" for free.
Mafia 2 hasn't been, though. My one is now called "Mafia II (Classic)" and the definitive edition is a separate purchase, at a hefty NZ$59.95. Makes sense, due to the work to upgrade it to the new engine, but a leeeetle discount would've been nice.