Something has come across my mind just now. As I walked through the mining world 1-9 it seems like all the open caves systems have been gutted out. I am sugesting we reset the mining world. One reason is that people are requesting for it to be in effect. And so many caves have been gutted out of its visible ores. If you would imaxorz would put this in to effect.
You can strip mine, and Peaceful and PvP still have plenty of untouched land, there is still sand/dirt/stone to harvest in mining. Most likely we will reset both mining and nether when we upgrade to 1.5. You CAN mine in PvP/Peaceful, but don't mess up the terrain. (aka digging out large holes to bedrock)
Ok that seems fair but, I kinda was expecting that answer but ok its fine. I just like open ore caves better.