The specific answer is: it's been mentioned, but little detail given; we do however, know there's going to be a closed alpha in the next year. For the past 6-8 years Brebion has been working on individual pieces of the game▬ getting deferred lighting right was one piece▬ and for the past year he's been putting the pieces together into his one engine. He's going to write his yearly project retrospective in about 10 days, which should be revealing, although only to the extent that he knows.
If I were to hazard a guess, I would say that the closed alpha is also the date that the merging is done, and the next one or two years afterwards will be filled making sure everything is perfect (to the extent that human error allows) and finally being more decisive about what art is going into the game. Since the forums would have exploded again with any hint that the closed alpha had begun, IA would be reluctant go any farther, probably choosing to keep it closed into beta, or even release, just to keep progress controlled.
The talk lately hasn't really been about release, but about current contribution quality, and that the reason so many are pending review is because some of them are just on the blurry line and others would experience emotional backlash from being told "no" after all their amateur work. It seems like the forums have been far more effective at increasing contributor skill than it has at producing usable things.
Well, I guess that's not really the uplifting news everyone looks for, but if they decided to announce that all the time they really would have vaporware on their hands.