Ether mining difficulty bomb - when will it happen?

Ether miners this is worth reading if you don't already know!

Proof of stake is coming for Ether, but when? There will come a point where it won't matter if the network hash rate is going up or not and the "bomb" will take over at which point the difficulty will increase regardless of other factors. As long as someone, somewhere is still mining ETH upon the switch to POS, the bomb will still cause an exponential increase in difficulty. This is intended to prevent the old fork using Proof of Work from being viable so that a situation like etheruem classic can be avoided where not everyone supported the new fork.