They're working towards a PoS mined coin. This required ETH to mine so only those with ETH can mine. You could call that centralization. ETH will be fairly decentralized. Of course there will be a new coin that comes out and gets better decentralization but ETH will be pretty good.

There will be 1000s of coins that reach a billion $ marketcap with tons of users. This is where the true decentralization comes in, when there are 1000s of different coins distributed through the world.