[maps]

Which won't happen since the 'cost' of mining is electricity and hardware costs which for some miners is probably very close to zero. All this is going to do is shuffle out the miners who have no efficiency.

[Angostura]

Sounds like an opportunity for someone to get control of more than 50% of mining capacity.

[mannykannot]

At which point, could you unilaterally hard-fork it, e.g. to fix this problem with the difficulty-adjusting rules?

Though if that is an option, I would guess it would be more likely for a coalition of miners to choose to do so before any individual achieves 50%.