What would happen if the miner reward was proportional to the difficulty?
As more and more people mine, the reward would be bigger and bigger, allowing for a more fair distribution of coins for late comers, IMO.

I think a good formula for miner reward would be reward=0.01√difficulty (square root to discourage inflation), which would give 5569 bitcoins right now, or 24 million bitcoins per year at the current difficulty.

Of course the early adopters would not like such a system, but they are the minority IMO. As long as the majority benefits from such a system, I think we can do it.