Anyway, wandered off track a bit - it is possible to build a whole town (2000 homes) with one commercial super-contractor. However it is bumping into local democracy issues already so anything bigger is always going to need a proper mayor. Like a real city.
Utilities are controlled, we get our internet from Verizon (FiOS), trash, etc. but with the controlling agent as the broker and bundle negotiator.
There's a semi-elected board that runs the place, I think 7 of 12 are developer people and the rest are elected from the neighborhood. The condos each have their own controlling boards.
AS the neighborhood gets more and more developed, the developer will be ceding more and more slots from the board to elected officials.
I don't know if there are any plans for a mayor, but I think we'll end up with around 15-20k residents once everything is complete.
It more or less works.