I would love to do a one-click deploy to express/everyauth (for node) or app simple sinatra/warden app for the ruby folks.
Once you define the auth requirements and the API itself, there's little left beyond the boilerplate.
I imagine a simple, closed-loop solution with semantic versioning that consumes the blueprint like a config file. As we update the blueprint and bump versions, the appropriate changes would be reflected on the server. Your live environment would be naturally in sync with documentation, and it would be versioned and tested.
Such a solution entirely frees us up to focus on the app itself, which would be very cool.