Yes it's true Kingdom Hearts 3D will come out next year in 2012 in both Europe and North America. This information was revealed via twitter and facebook page.
Square Enix also revealed the following gameplay details. The game will feature:
Dual protagonists - Play as the two most popular characters of the franchise, Sora and Riku.
"Free-flow" action - Enjoy fast and effortless movements while interacting with the environment and performing acrobatic attacks.
Brand-new creatures - Dream Eaters inhabit the Sleeping Worlds, and are split into two categories: Spirits and Nightmares. Recruit over 50 different types of Spirits as allies to fight alongside Sora and Riku.
New Disney Worlds - Beloved Disney worlds and characters, such as La Cit des Cloches (The Hunchback
of Notre Dame), make their series debut.
Story Progression - With updated looks for Sora and Riku, and the impending conflict made clear, this title is a big step forward in the series.