Just as I had predicted Vodafone is coming to party and opening up 4G for prepay customers!
http://www.stuff.co.nz/technology/digital-living/30003143/vodafone-to-offer-4g-on-prepay
At least according to the stuff page ...
I have already bought a prepay sim along (along with a free locked phone that is) ... now the question is when it is coming to Dunedin!