One thing I would like to see implemented is some sort of hunt or "whaling" for some sort of animal. Maybe since it is a post apocalyptic world there are mutated flying whales from the nuclear fallout? I think it would be pretty cool if there was a whale hunting mode. You would shoot harpoons and stuff from your airship and chase and catch them and whatnot. It could even be turned into a competition type match to see who can catch the most whales in a certain amount of time or whatever.
Sorry if this sounds ridiculous or silly to you, or really difficult to implement, but I think it would be awesome fun and really cool to have whaling in the air.
It would also fit well with the nineteenth century feel of the game.