Hi everyone it's Xebs, As some of you may know there was a Kingdom Hearts HD 2.5 ReMIX launch event at the Walt Disney Studio in Burbank, California. At the event, they were given a sneak preview at Kingdom Hearts III footage.
The footage shown off concept art, new Heartless, a new town titled "Cable Town" with Sora in a library or study room and new Keyblade-gun attacks for Sora. Sora was shown in various Kingdom Hearts II outfits including Valour and Wisdom form. To expand on the gun Keyblade attacks, Sora's Keyblade transforms into dual guns and then transforms into a cannon. Also a large cross resembling 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.
Hopefully new information will be released to the public in Japan at this years Jump Festa 2015.