Zilean's W

I know that a lot of people dont play but i was hoping someone could help me out, i thought i remembered reading somewhere that Zilean was gonna get his W (Rewind) changed so it cost no mana to activate? sorry if there is already a discussion about this, just wanted to know if he was still gonna get the change or not. as someone that mains Zilean and brings him to mid lane, i can say that i need the mana i use on his w to throw another bomb. xD