I hope one day CCP will add all elements known to date to the game where you can not just refine material in one refinery but you need special refineries to refine rare items like Osmium and Francium. I feel industry has alot that could be done with it to create market niches for industry people and making new markets and building materials. Possibly making new systems also where you can use T4-T5 ships and guns. But if you go back into the old areas like High sec and low the dps is scaled back to that of T2 ship.
Possibly also bring in more rock types like quarts. With special refining you get Silicon from SiO2. Things like this. Adding Hematite, and much more.
Also would like to see material used for building reworked. Like fore instance lots of iron for the basic ship while ship components like afterburners require very rare and hard to make elements. Same goes for electronics.
Possibly the use of chem labs also for breaking down elements to make pure elements.
Also could be fun to add some story line like adding another faction that players can play. Maybe like adding a system that explorers can eventually find leading to a new race to play in the game. Almost feels like game needs something that not of the norm to get new attention.