There is a lot of Maoris in Australia, taking advantage of mutual settlement and work rights in each others Country, I have met Kiwis in Sydney, Alice Springs, and Aussies in Auckland, so its a two way street, they seem to prefer that.
Having been to both Countries, they both have different characters and history that created the unique national National Psyche of each Country, I have had the opportunity to attend ANZAC day in both Countries, it is marked in a similar way but with their own take on it.
It would be a shame for them to merge but then its their own free choice, one thing for travelers is that UK passport holders don't need a Visa for NZ but an ETA for Australia, that could change to ETA for all, immigration rules could change, Aus got enough people, whereas NZ is crying out for more suitably qualified people as it is under populated for its size.
mostly bollocks put out by the 'federal faction' and depends what part of godzone your in.
on the NZ MAINLAND ( the south island that is, not the poncy north island bit) there has been various 'South Island Partys' over the years ( and one attempt to blow-up the inter-island power cable ) and theres more of a following to an independent south then a merger with OZ.
the sooner the better too............... speaking as a NZ Mainlander.