Wow. Clearly a complex issue. I see that there's a conference on this next week run by the Commerce Commission. Hopefully it will all be sorted by the time we're cabinetised in 2010.
I guess my only comment would be that there must be a point at which it's simply not economic for another supplier to put additional equipment in a cabinet. For example, our local cabinet will serve (I guess) a few hundred homes. If half have broadband, and say 10% of those use Orcon, then that's really not a very large number.
Then I should hope I get lucky, because my exchange provides a broadband service to nearly 10000 homes.