NZ 777's will have the seating 4-across - the cabin is similar width to a 747 lower deck (and significantly wider then the A330-340 cabin). To illustrate:

United 747's are 7-abreast in Business (2-3-2 lower deck), as are 777's.

United 747's are 9-abreast in Economy (3-3-3), as are 777's (2-5-2).

Airbus used this additional width against Boeing in marketing (A330 and A340 ads had the tagline "No middle seat in Business", with market research to support the view that Business passengers hate middle seats on long haul).