Fascinating question.
I don’t know that it will be this year, but at this point I think it is likely to happen.
Bitcoin core has not shown any signs of upgrading their tech. All the bitcoin hardforks - upwards of 15 last time I checked - are only encouraging the core team to stand put imo.
If not this year, then most likely by 2019, I think we will see Litecoin as the top market cap. The lightning network is coming along swimmingly. Atomic swaps are on the way, and Charlie is hinting at ICO’s on the Litecoin network. Add to this the rumors that Litecoin will be a payment option on Amazon soon, and you have a monster in the making.