I thought for sure it would take until the end of 2018 but it looks like this summer ethereum might pass it up. With the turmoil around BTC potential splitting, it might be very soon. IMO this is healthy, we will always value bitcoin for being the one that started it all, but it's time for a more dynamic and adaptable currency to take the lead.
There is a huge chance for ethereum to surpass bitcoins since it is really showing some potential in the market. Minex coin is also good because the platform is successful but i do not think that this altcoins will really surpass bitcoins because the price of btc is very far away from this alts.