The NZ Government have announced free to air digital TV will be phased in from next year. Now, all you need is a DVB-S card and MythTV. Did you know New Zealand had a MythTV users list? There is also lots of useful information at the KnoppMyth wiki page for NZ and, of course, the WLUG wiki.
Update: TVNZ and BCL both have press releases out. The content will not be encrypted, but the technology hasn't been anounced - probably not HDTV.