Gothfather: Bummer. But I would rather a game be delayed to fix issues then do a release and patch approach to development. So while disappointed in the fact that we have to wait a bit longer I applaud Hello games for having the courage to delay things to fix issues that need fixing.
Well, since he actually announces it on the playstation blog, and he specifically mentions final playtesting and q&a as reasons, I'd go with an about 99% certainty that it's at the "request" of their major sponsor, partner and indirect publisher on consoles, namely Sony. This would also explain why distributors got wind of the release date change so early, that it actually was leaked from Sony.
So while I'm /sure/ they won't do anything crazy - you might not want to be too surprised if it turns out the game was delayed to insert a Kart mode. Or that the game will have autopilots and auto-aim for every single action. And that elements that would upset creationists have been removed. While all and any advanced features on terrain deformation and faction AI, fleet systems, and so on, have been removed from the final release to avoid console issues. That somehow should be fixed just in time for the first DLC.
Oh, and did I mention that there will be a sniper-rifle and twitch controls for the ground movement, so you can strafe back and forth and snipe antelopes across the planet with auto-aim? Afterwards, if feedback is less than stellar for the changes, then it's of course the developer's fault for making an initially "flawed game".
Trust me on this one - you do not want anything to be delayed because of Sony Q&A.