I too was looking for return premium cabin inventory from SYD to the States on January 1, 2007 and found none. It may very well have been zeroed out from the outset because that day is both a holiday and coincides with peak travel season to and from Australia.

Here is a thread I just started the other day with some tips for finding such inventory 331 days out based on my personal experience. Calling at 3-4 a.m. CST or shortly thereafter seems to be the best idea for getting first dibs on inventory as it is being loaded into the system for the first time.

I would highly recommend putting in the effort and gobbling up the very first return inventory you can (331 days out would now be 1/5/07, I believe) and try to switch to a more desirable return date closer to the beginning of your trip. Or, if you are on UA metal only, you can waitlist for the premium cabin.

As far as flying on NZ, anecdotal evidence suggests that NZ is being very tight with its inventory in its new business class product and is generally releasing seats approximately 90 days out, if at all. AC is a little more liberal with its inventory, but the return flight from SYD-YVR stops in HNL just after midnight and requires you to deplane and reboard, which is hardly ideal.