Well the new Kingdom Hearts seems to be pretty incredible, despite the fact of having color zoo animals as partners.
The story goes, Sora and Riku go under the mark of mastery test, some of the worlds were not exactly saved, they entered a deep sleep and are being attacked by the new enemies, The Dream Eaters. There are two kinds of Dream Eaters, The bad ones called Dream Eaters and good ones called Spirits. Spirits eat bad dreams and replace them with good ones
A few worlds have been confirmed in scans
[list][*]The Three Musketeers
Pranksters Paradise -aka Pinocchio
La Cité des Cloches - aka Hunchback of Norte dame
Traverse Town - with new Districts
Symphony of Sorcery - aka Fantasia
Tron Legacy - no official name yet
No news about any final fantasy char in this game, by the scans I have researched, there might not be any.
As for fighting mechanics of the game: Deck Commands is back just like Birth By Sleep & Re:Coded making it possible to blend and create costume decks of attacks. I'm not going to be for sure on this but this game might have Command Charge attacks such as Wingblade, Ghost Drive, Charge blade etc.
Cross overs: As we all know "The World Ends With You" will have a cross over that may take place during Traverse Town only. This alone will be really incredible to play though since TWEWY is a good game.
I will post scans on a separate topic since they are too large to post along with this.
Last but not least a bundle has been announced.The bundle will feature some sort of AR Cards, the game, and a Lim Ed Kh3DS Theme DS
No news if this is Jap only but the sites never said anything about being jap only, so there is that hope it will be US as well.
Thats it for now, I will keep up with the info as I go through the scans.