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.
We cannot all predict what would really happen on bitcoin sooner or later. A lot of threats are arising nowadays such as new cryptocurrencies that are showing up their potential on dethroning bitcoin. The best thing to do right now is to start investing on other cryptocurrencies so that if ever bitcoin fell down, we still have a source of income. Having that idea doesn't mean you should stop supporting bitcoin instead we should have faith and keep our hopes high on it.