How to maintain a Drupal project on GitHub
Technically, this post on SO covers pushing/pulling from multiple git remotes. In your case, it sounds like you'd set up 2 remotes (git.drupal.org &amp; github.com), pull/push from github.com as needed, then push to git.drupal.org when you're ready to publish updates.

As far as the politics, checkout this thread on g.d.o. It might contain some thoughts/insights from other people who are in the same situation you're in.