Spells, magic items, equipment, are all tools in a toolbox you use to interact with the world. If a tool does nothing but +1 damage, it's not letting you interact in a new way that could be fun and meaningful. Zelda games tend to be really good at giving you fun tools (in Wind Waker, for example, using your Heavy Boots to stand on a spring and compress it, then remove them to spring up, then use the Big Leaf like a glider to get across a thing).
Emergent gameplay is definitely where I want to see work being done on a game. Games that have "machinery" like Minecraft (although limited) open up enormous possibilities. Coding "social machinery" and "economic machinery" into the game, and quality AI, could have incredible emergent results. It could also just screw it up real good, but that's fun too.
So rather than Fire, Fira, Firaga (Final Fantasy), I want to see a fire spell and a water spell and if you combine them you get a steam spell that acts like a cloud and doesn't destroy the loot. I want a Detect spell that has as its material component the object to be detected (so you carry a key with you so that you can Detect Keys). I want the designer to make sure there are six ways to do anything, and create an environment where the players will probably think of six more that work too. How many ways would you go about stopping a leaky pipe IRL? How many would basically work but aren't the best practice? I want all of those, not just "go to the basement shutoff valve and press X, then get a pipe section, and go to the leaky pipe and press X, then to the valve and press X."
We are gonna see some really nice stuff happen with games when we get 1mm-scale voxels with an expansive gameworld. Blood flow through veins and arteries, damage to specific parts of the brain causing emergent AI malfunction, crafting sweet gadgets, etc. Heck, with 1cm-scale voxels you could have emergent weapons like guns and stuff, and arteries defined as part of some muscle or skin tissue, organ failure as a result of damage to organ voxels, etc.
And we've yet to really get into ecosystems and fluid flows on a big scale.
I think with that kind of computing power and programming work, it would be cool to play a spellcaster. Sit around all day mixing up shit and testing spells. "What's Jimmy09 doing in his tower?" "Oh just trying to figure out a tornado spell." Would be awesome.