Vitalik is the number one factor of Ethereum. So if he will going to leave Ethereum would really going to affect the current status of Ethereum. But it's not only Vitalik who made the Ethereum great it's the whole team who worked behind it. So we will be sure that Ethereum will always find it's way to make it success. And personally I think Vitalik wouldn't going to leave the Ethereum. Let's hope for it.