this new fork of ethereum changes the whole system. it will no longer be Proof of Work (PoW) but instead it will be Proof of Stake (PoS). and this means you can no longer mine ethereum and all those who have already invested in some mining equipment are screwed because they either have to sell or mine something else.

and what happens is that those who have more ETH will earn more now because they will be rewarded more. like the Ethereum foundation who is holding the premined 72 million ETH tokens.