Right now Minecraft has a bit of love hate relationship with updates. They add new features while simultaneously forcing players to either create a new world or travel long distances to load new chunks. Strangely, no one seems to be discussing fixing this fundamental problem.

What Minecraft needs is a way to update chunks the first time they are loaded in a new version thus generating new ores and structures. In order to achieve this without messing up other builds Minecraft would have to know if a block was natural or artificial (created in the original generation of a chunk or placed by a player, piston, etcetera.

The easiest way to discover this kind of information would be to add it into the chuck data. A simple bool (true or false) for each block would surface. Alternatively, Minecraft could generate a chunk with the generator that was used to create that chunk then compare to the current state of the same chunk, any differences would be assumed to be new blocks (in this case the version used to generate the chunk would need to be stored).

Even if Mojang didn't do anything with this added information it would be a boom to mod makers allowing them to convert preexisting worlds without risking builds. The sooner such a system got implemented the better for older worlds. As long as the informations there, down the road an "up dater" can be made.

Thanks to Invictus13307 for his post Command to Populate Existing Worlds with New Ores. I'd been thinking about this for a while, but he really inspired me.