I think something I'd like to see in upcoming rpgs is a more active battle system. Kinda like a cross between Legaia stuff and Saga Frontier 2, but more like an action game. Imagine a battle starts and you're given an option to fight either 1 on 1 with an enemy for a more detailed battle, or group vs group for a simplified and faster fight (Saga Frontier 2), and in the 1v1 fight it was almost like a fighting game where you could associate different basic attacks to controller buttons and combine them to form special attacks or combo strings. It's boring to simply hold down a button all day for basic fights, but sometimes you just want that easy answer, so you can choose the group fight and essentially press (button) to win.
I also had this really fucking radical idea for a battle system in more action rpg style where you did special attacks based on your terrain. Think geomancer in FFtactics but to a whole new degree. Like if there was water in the immediate area you could use it to heal players or attack an enemy, or if there was a patch of grass you could use that to grow vines amd plants to ensnare your foe or gas them with different plantlife for sleep or poison or paralysis. Of course, in the instance where an element isn't available you'd have an option as well. You could carry instant element mods like a bottle of water or a torch or a plant, though these would give you smaller effects depending on quality. I know it sounds like it's been done before, but I can't think of any game that ever portrayed it in this way. You have so many games that give you alchemy for making items or changing them, and it's pretty standard rpg fare to have elements and elemental spells and such, but this would be less like a spell and more like literal field manipulation, almost like in Avatar TLA. Actually, when I think back on it, it reminds me a lot of that show, but more in a magical way. This would be more science fiction. Lots of babbling, I know, but hey...maybe one of you aspiring video game developers will see this and throw it out there for use one day....I can dream.