Square Enix have opened up their own official Kingdom Hearts II site. Contained on there is information on the storyline, characters and two of the worlds in the game. The storyline section covers the stories of all of the KH series, the first Kingdom Hearts, Kingdom Hearts: Chain of Memories and an intro to Kingdom Hearts II.
Profiles on the three main characters Sora, Goofy and Donald can be found in the characters section, as well as some artwork pieces and some footage of in-game movements.
The World's section is where information can be found on the two worlds of Mulan and Hercules. The Download part of the site has a new wallpaper to pin up on your desktop. The last section contains system information and specifications, and also a new trailer to view.
The trailer starts off with footage of Namine and the Blond Haired Kid (who now is known to be a playable character). Then we see Sora visiting several worlds, such as the worlds of Hercules, Mulan, Aladdin and Halloween Town. Sora's new overdrive mode can be seen in action and the trailers ends with a reminder of the Deep Dive trailer shown at the end of Kingdom Hearts: Final Mix.
Link:
http://www.square-enix.co.jp/kingdom2/
Kingdom Hearts II is due for it's release in Japan and the US, some time this year.