So this isn't really a mod request, but rather asking how difficult a mod would be to create.
My fondest wish for Minecraft is to have a world that is all Ocean, but all those teeny tiny little islands would have different biomes. I guess in technical terms what I'm talking about would be for every biome to handle land generation like the Ocean biome, mostly deep water, but with a chance for tiny islands to spawn. So there might be a Forest biome in the world that didn't manage to spawn an island at all, it would just be open water. And that would be perfect for me.
So while I've done some little mods that add items and mobs to the game, I've never done anything that messed with the whole world on the scale I'm talking about. So I'm just kind of asking the experts...how hard would that be to do? Thank you!