Ethereum is planning to start proof of stake concept at the end of this year / early next year. None can forecast how it will influence the currency. There is a high probability that current Ethereum miners will not be ready to shut down their existing mining capacities. This will result in new fork, which we saw in bitcoin during this year. 
Proof of Stake is definitely going to stir up change among the different players on the Ethereum network. Like any new change, it comes with some important benefits but requires the cooperation of all those parties to succeed. Since many miners already hold large reserves of Ethereum, there's a good chance they might not see PoS as a huge threat (given the opportunity to gain ETH from depositing some of the ETH they already have).
Miners will act selfishly as we have seen many times before. I think they will fork away or will go to ETC.
Thats why i think-> when ETH goes POS, i think ETC will moon.
Once Casper's out, someone will have to do a commercial analysis to see what the Risk/Return is for switching to PoS vs. forking. Miners can sell their hardware, will have lower electricity costs and lower staff costs. It's conceivable that this change could actually be more profitable for some miners.
