Actually, chocobos in battle is NOT new. They might be considered to have a bigger role than before, however, just based on the number of different uses they have for one single game, however. Personally, I hope color will mean nothing but color. I've always been a fan of black chocobos, and I'd like to have a black one without being pigeonholed into using it for one particular thing and nothing else.

As for your crazy ideas of new chocobo types (flaming, mechanical etc), I highly doubt it, and it sounds a little cheesy.

And I'm pretty sure chocobos are not flying animals. Like ostriches, they're flightless.

And a chocobo being able to run on water is ridiculous. In 7 they could only go THROUGH shallow waters. Yellow chocobos can already go through shallow water in 14.