At the Kingdom Hearts HD 2.5 ReMIX North American launch event at the Walt Disney Studio Lot in Burbank, California, Square Enix has shown new Kingdom Hearts III footage and revealed that they will release new information in 2015. The new footage showed concept art, new Heartless designs, a huge town titled Cable Town with Sora in a library/study room and new gun Keyblade attacks for Sora. Sora was shown in various Kingdom Hearts II outfits including Valor and Wisdom form. To expand on the gun Keyblade attacks, Sora's Keyblade transforms into dual guns and then transforms into a cannon. Chi was also written on a blackboard in the study room, this may be related to Kingdom Hearts χ[chi] but this is simply speculation. Thanks go to @churroz for the information.
Update: Siliconera has posted their impressions of the footage. They reveal that Yoko Shimomura, composer of the Kingdom Hearts series was also at the event and performed a couple of the series' most famous songs. They have also included what Heartless they believe were shown. You can read them below.
Square Enix held a Kingdom Hearts HD 2.5 Remix fan event in Los Angeles earlier today. The event began with Livan playing Kingdom Hearts songs like "Kairi" and "Hand in Hand" on a piano. Surprise guest, Kingdom Hearts composer Yoko Shimomura joined him for duets of "The Other Promise" and "Dearly Beloved."
All the way at the end was a little teaser for Kingdom Hearts III. Tetsuya Nomura, Kingdom Hearts series director, said it was too early to show worlds, but wanted to show fans something new. We were not allowed to record any footage from the teaser, which opened with concept art for Heartless in the upcoming game. One enemy looked like a souped up Blue Rhapsody Heartless with flames around it. Another enemy looked like the Soldier Heartless type with angel wings. A new enemy, a large Heartless with a bull-horned helmet, looked like a knight. There was also a tiny Archer heartless holding a bow with a quiver on his back. Some of these were sketches, but others like the Knight Heartless were 3D models.
A clip of Sora wearing his Kingdom Hearts II costume was shown next. He had the Oathkeeper keyblade in his hand which could transform into a gigantic gun. When fired, Sora would rock back a little bit and a star-like projectile fired from the bazooka-like weapon.
The next scene showed a town with white houses stacked on top of each other and huge windmills. This town seemed grand and tranquil, not unlike Twilight Town, but instead of a sunset palette the buildings were primarily white. A plaque underneath said "Cable Town" and the camera zoomed into one of the buildings. Doors opened and the camera panned horizontally by chess pieces (one of the pieces had Mickey’s head on top) and a chess board. The scene switched to Sora entering the room and walking towards the chess pieces which were placed by a window. Sora picked up one of the pieces and the trailer ended with a message promising more Kingdom Hearts III news in 2015.
Update 2: Square Enix has told those who attended the event that the footage was only intended for those who attended the North American and European launch events and that more information will be revealed in 2015. This is likely due to the footage still being quite raw. Thanks go to @churroz for the tip.