Well I emailed them about NZ for the N900 and got this response

"Dear Customer,

Thank you for your e-mail. For Maemo device is application called Aura prepared with maps of Australia and New Zealand.

This application is under the construction and should be released in close future.

AURA comes with all data pre-loaded, so it will never let you down. Data storage is faster, more stable and cheaper than data transfer from an Internet connection. Wherever you are, use AURA to find your destination without any roaming costs. Places, addresses, maps, wiki information, city guides, navigation and voice guidance - all are pre-installed.
In case of any questions and feedbacks, please don't hesitate to contact me."