Throw out GameMaker and XNA and anything else you can think of, as it does not have a fully fledged engine for Pokemon already.
Hopefully people are listening. As I have said before, we need to create new tools. This is what all new engine needs to have in mind. GameMaker, XNA, Python, Java, etc is not meant to create RPGs, so you can only guess that it is harder to produce something with it.