I really want to see better combat:
-Expanded weapon movesets to better differentiate between the weapon types.
-Tougher enemy AI. I'm not talking about padding them even further than they already are, but giving them the capability to counter common player strategies. Doesn't matter how much damage they do if they never hit you.
-More freedom to fashion-up rather than everyone wearing the same one or two sets for the same world stage.

Edit: Copper golems. They really need some engaging way for more advanced characters to gain some side-copper without spending their time staring at a hole in a biome that they have already far outgrown.