ZDNet Australia asked local Dell's spokeperson Paul McKeon about their Ubuntu offering and was told that the decision hasn't been made yet. He gave two reasons: multitude of languages in Oceania and support problems.
I can't speak about localization efforts in that region, but the second claim is a bit peculiar. Systems bought on the US site are supported by Dell only on the hardware level. Software-related support is optional and handled by Canonical. And Canonical lists 32 companies that provide commercial support for Ubuntu in Oceania (27 in Australia and 5 in New Zealand).