Orbx were working on an NZAA until the developer got sick about 4 months ago (hope he's on the mend). On their forum they said they'd keep people posted on its progress but they haven't and I got a rather patronising and unhelpful answer when I asked if there was any news. I guess nobody knows whether/when they'll pick it up again, - I imagine they're all very busy trying to get things compatible with P3D2 and new work has probably got put on the back burner.
If NZAA gets the full OrbX treatment it'll be fantastic (especially for us Aucklanders) and I think a lot of people who have OrbX NZNI would buy it. The existing NZAA, although probably impressive at one time, is a bit painful to look at these days, at least mine is. I'd like to see proper air bridges and all that good stuff...
