The only thing I have ever seen at Disney in regards to Kingdom Hearts is at the Japan Pavilion in Epcot. There is a small section in the store where you can find Sora action figures and some other items. I do believe they were a little pricey, about $30 for the action figure.
As far as a ride is concerned, your guess is as good as anyone's. For some reason Disney hasn't taken to this franchise like the gaming/Disney community took to it. They are great games and just seeing characters around the park would be good for me.