My understanding through my knowledgeable contacts is that NZ is VERY interested in two C-17s, and that work is actively underway to make it work financially and operationally.
Who would have thought Australia would have 8 (gusting 10) C-17s a decade ago? Before that it was just a notional project sitting on a shelf somewhere. But then the Boxing Day tsunami and the Bali bombings happened, and the Hercs were caught lacking in their ability to rapidly respond to these large-scale disasters.
Since then there has been the Japanese tsunami, cyclones at home and in the Philippines and Vanuatu, MH17 recovery, not to mention ops in Afghanistan and Iraq, and the withdrawal of heavy equipment from Afghanistan.
I agree the C-17 AND the C-130 both have a place, both in strategic influence and in tactical ops, and would not be surprised to see NZ buy C-130Js or A400Ms in a decade or so...