I must know one thing. Because of all the players, buldings and ect, will many ores be in the map left? And i have one idea. In hell, or other realms make shrine like structures with treasures in them.
That's an idea for the next map we make, once there's need for one (there isn't now). We currently have a brand-spanking-new map though, so the ground should still be pretty plentiful.
I've made the suggestion of mine-shafts that hold certain ores. not all in one place, but placed in spots of 1-3 ores in solid stone.
In the uber-chasm in the corruption I think I should create a mine which is hard as shit but it frequently has 'cave ins' and replenishes it's ores as well as normal items.
The locations of the ores and goodies would change every time and the mine would only 'cave in' when about 90% of the ores are gone in the mine.
Also this would only be implemented later on when the map is running dry, right now there are more than enough ores!
The chasm in the corruption is THE BEST PLACE to farm ores. After spending two hours down (which were really my failed attempts to cross it) I came up with enough iron for an entire set of armor, enough gold for tools, and still with enough left of both to make furniture. As long as you have some sort of ranged weapon and a grappling hook it should be easy to get into the open side caves where all the goodies are.
I don't have a demonite pick, so I can't mine in the chasm. I've been trying to leave veins of silver and below for others though.