However, the way it was presented is rather.. well done? Instead of going all-out with everything, and have it written off as another wishlist, he first presented it as if he had very limited access to the stuff, recited from memory or brief info sheets. Quick descriptions from artwork, small overview of game features, some interface, etc. He refers to specific points in the trailer, having explanations for minute details, and so on. He has all the designs ready, all names and so on. However, to avoid inconsistencies, he pretends not to know much, instead portioning out his stuff little by little. This way, nothing he says goes against anything he will say later.
If this is fake, it has accomplished its objective. Every Pokémon fan site has a thread or two discussing it. Many fans have swallowed the bait completely. Many are sceptical (myself included), but even they agree this is very well crafted. Any news from GameFreak refusing what we've been presented could blow the list completely. On the other hand, any news from GameFreak not refusing it would just cause the debate to stir even higher.
If it's legit, however, Mr. XY should either be looking for a new job soon, or he has done his job well and generated a fantastic amount of PR. Whether or not his bosses wanted this to happen is uncertain, but either way it has got the fans pumped for the game.
Well, some of his ideas do look cool~ The typings look interesting; I hope the new pokemon for X&Y will be similar to some of the typings listed! Or at least, I hope the new evolutions do~