Sorry, but no, I've changed my mind and not planning to add the centauress scene in the near future. Maybe closer to 0.13 but we'll see.
As for the Steam I already disscussed it some comments below (about a month ago), so no, sorry.
From the bright side I can only say that I'm planning to release builds more often now, so the next public build would be in the beginning of the next month.