My personal opinion has always been that Pixar ruined Disney, before they gave us great movies like Beauty and the beast, Mulan, snow white, and many more and now we just get 3D movies which I can't stand.

So I would be really sad if we had to meet Pixar characters in the Kingdom Hearts world, since I really love that game
Though I understand all of you who like Pixar and want them in the KH series.