I heard that a couple of guys in Christchurch developed the sound grenade app for the iphone. Has netted them about $100,000 each thus far; but thats the only success story i've heard of in NZ to do with the app store.
I'm chipping my teeth on this as well. It seems that you either make it or break it with iPhone development, and from my limited experience the second you develop a Windows app, there's an absolute horde of Mac and iPhone users asking when the port will be finished. It's quite the phenomenon really.