I was talking to someone on Facebook how Sakurai didn't specifically say it was "N's Castle", but rather "someone's castle". This guy is a big-time supporter of Ridley, and he uses the fact that Ridley was never explicitly mentioned by Sakurai as a means to justify that he might be playable. In comparison, he says that many other characters, including Takamaru this past Monday, were revealed right off the bat and didn't dance around the issue at all. He thinks that this might mean N could potentially have a bigger role in the upcoming Super Smash Bros., and wants to wait for a more dramatic reveal. Someone even suggested that N might be playable, but I highly doubt that.