I think Sylveon is an elaborate troll success by Game Freak.
I'm not fooling for it.
Okay, I don't care if you're not "fooling" for it, but it was a successful trolling by GF regardless of your thoughts. It's got the community worked up over the type an there's quite a bit of hype for Sylveon's type now. While I have an opinion (Dragon), I'm not too passionate about it.
Hmm, I feel as if at this point there's so much hype that anything but a new type would be underwhelming. Wouldn't it be weird to hold this over us and suddenly go "it's a flying type, dur!"