Even though I wouldn't trust fud as far as I could throw him, this seems like a reliable release date. If I were you I really wouldn't hope for a December release, just dont see it happening. But if we're lucky we might get a product showcase in December, which is guess is better than nothing.
Well, even the most honest prediction from NVidia is still just a prediction. Q1 is the scenario IF all goes well, which hopefully for them it will. In that IF are: IF the A3 silicon is rock solid, IF TSMC irons out their fab issues, and IF the drivers are in order and all other materials are set. Three big IFs, at least one of which is completely out of NVidia's control. So even assuming that is their honest opinion, there is no guarantee that they will be able to meet it.