Considering how unrefined and, frankly, disappointing X/Y was as a whole, I just expect GameFreak to improve on the formula already at hand. Considering Gen. V was an evolution of Gen. IV, this makes sense.
Things that need to be improved include, but aren't limited to; expansion of amount of new Pokemon added (the amount of Pokemon added in Gen. VI was laughable), improvement in graphics (especially during 3D battles), improvement on story, and harder difficulty modes. X/Y really needs to be polished, because it's not.
Also, Mega Evolutions were terrible decisions from the beginning. Take them out.
It's kind of hard to take out Mega Evolutions. They are an important game mechanic that if they take out, a large majority of competitive battlers will be pissed. Mawile would go back to being damn near useless.