0.6 is already going live in the sense that we have clients doing pre-launch content population, or will very shortly... there's a README with it that explains how to get going. You can use an npm dependency pointing at the git repo rather than npm link if you wish, which is how we're using it in production for now.
Everyone has had a good laugh at this sentence:
"How to make a website with Apostrophe 0.6 unstable"
But for now that doesn't seem entirely unfair, although with us moving into production we obviously are not making bc breaks every day anymore. (: