Google cleverly has chosen to make their G+ API read-only. So if you want to publish once to hit multiple downstreams, gee-willikers looks like you'll just have to do that from Google+.
If the goal is to increase community size and loyalty, ditching the hostility toward nyms would be a far more productive way to go about it.
(And releasing a kickass bi-directional API would eliminate a lot of wariness about migrating.)