Square Enix has just announced a Kingdom Hearts HD remix at the Tokyo Game Show that is happening as we speak! So far they have added a teaser site and minor information. So far it’s shown that Kingdom Hearts Final Mix, Re:Chain Of Memories, and Kingdom Hearts 358/2 Days will receive an HD remake on the PS3! We will add more when more information comes to light!
UPDATE: Square Enix also has announced a Kingdom Hearts Facebook browser game! Here are some details translated by IcyWind14 of Gamefaqs:
KINGDOM HEARTS for PC browsers (tentative name)

The world of fairy tales far.
The world is filled with light that light was wrapped, and a variety of the world’s creator.
Kingdom Hearts source of light, the key to protect it (key) blade.
I believed that as long as there is, the world is in the light of eternity.
However, the strong light cast shadows gave birth to darkness.
Darkness evoke anxiety and fear, the desire.
Darkness hidden in the depths of my heart, and began to spread to the world as chaos.
to pay the spreading darkness, those who wish to make a key light blade that mimics the (key) blade,
I started a round-the-world adventure.

Able to play with the browser of PC, social games for the browser of the first series. Become a hero, customize your avatar, players around the world in a variety of Disney. To expand the game, such as search and collect the material in various locations, such as the battle system to divide the outcome by card collection, a completely new element. How to enjoy as well, such as an enemy, sometimes in cooperation with friends!
UPDATE 2: The official Kingdom Hearts Blog “Message From The Kingdom” revealed that the cutscenes from KH 358/2 Days will be HD in Theater mode while Re: Chain of Memories and KH Final Mix will be full HD remake and will support PS3 trophies! Also the KH Browser game will have a card system with customizable avatars!
UPDATE 3: Kingdom Hearts HD 1.5 ReMix is to be released in 2013 and there are trailers being shown at Tokyo Game Show.
UPDATE 4: Remember the Kingdom Hearts 3D Tron Legacy Play Arts from San Diego Comic Con? They have finally been colored in! Square Enix has also introduced another set of Play Arts this time Sora and Riku’s KH3D clothing! You can check out images below: