LOL, I actually liked the world in KH2 simply because it gave me a break from the constant Heartless. Then again, because of it, they made a complete mockery of the actual movie and its music, which was so much better than the stuff they had in KH2. Still, it was a break. Then again, so was Pooh's world, and I hated that world with everything in me... I'm biased, apparently.
I haven't seen the prequel, but I'm sure I will soon because my niece will probably get it soon, and she'll want to watch it with her whole family. Joy of joys! However, it sounds just as bad as any of the sequels and prequels that Disney comes up with. I don't see why they just don't stop with the original- they're never good a second time around.
To your original comment, I don't believe that it will make an appearance in BbS, simply because the prequel only takes place about a year or two before the events of LM for the most part, and BbS takes place about ten or so years before Sora's story. Therefore, I don't see how they would intergrate the two. Also, the story line of BbS was probably thought up before the storyline in LM: Ariel's Beginning was finished, making it too late to actually put in.
Also, they're only using the more popular Disney worlds, and characters, as worlds in the KH series, and I doubt that the prequel will have gained enough popularity by the time that BbS is ready to be released.