Just thought I'd quickly mention that people should try to be mindful of spoilers. Not things like move tutors and such, but stuff about Pokémon appearances, trainers and their teams...that kind of thing.
Personally, I'm a little disappointed with the list of changes (though I skipped over Gym Leader / E4 / Champion information). Even if the plot is furthered, I was hoping that the changes would be significant enough to justify the two games piece. Perhaps I'm being skeptical, but unless the plot is far more intricately advanced than the initial information indicates, it doesn't seem like this is anything a regular third version wouldn't be.
Won't necessarily keep me from buying one of them at some point, but buying both of them is probably out of the question.