Ah, Xerneas. The first Legendary I actually wouldn't be naming XD. Xerneas just sounds so royal and majestic in it's own right. And is it just me, or is there a possibility that Xerneas and Yveltal will be the first Legendary Mascots with assigned Genders?
It's very likely you're right about the who chromosome thing, but then again it might be wrong. Despite that, Xerneas does have a feminine sort of look about it while Yveltal looks more masculine. We'll just have to wait and see
Indeed...I also have another theory that Xerneas and Yveltal also represent the cycle of Life and Death. Think about it, Xerneas is a deer in the forest, where lots of life grows and flourishes. Yveltal, on the other hand, is more close towards a bird of prey (Even though people say it's more like a Dragon, but I digress), hunting down it's next kill. The colors at hand could also be a clue to this, as Xerneas is blue and Yveltal is red.
That's an interesting theory. Xerneas does remind me of a deer and Yveltal does remind me of a bird as well. I honestly don't see how they would think that Yveltal is a dragon, but hey that's there opinions. I was thinking that Yveltal, while looking like a bird of prey, might also be like a bird of the desert. I can just see it flying above a desert, but that's my personal opinion. I also see where you get the idea from their colors. Blue is often associated with water, which of course brings life. Red in Egyptian mythology is associated with the red sand which plants cannot thrive in. Both of your theories are interesting, but we will only know the real story when it comes out this October
It's not even for sure yet if there WILL be a Poke'mon Z. It was the same thing with Gen 5. People were expecting something like Poke'mon Gray or whatnot. But instead, we got sequels. It's not for sure yet.