I don't think anyone can argue that he lost them sales with that Twitter fukkery of his, especially with an already antsy group considering all the negative shyt we'd heard about the nextbox up to this point.
Twitter got another football on its helmet.
Lets be real, none of this stuff 9 months before the release will really affect sales of either. This stuff only matters in fanboy wars. Both will sell out before Christmas and eventually most hardcore gamers will end up with both anyway. The winner this Christmas will be decided by whoever can manufacture more units. And beyond Christmas tweets from an ex Microsoft employee from march 2013 will not even be in the consciousness of consumers.