To address this, Gazillion is preparing to scrap the current hero token drops and institute Eternity Splinters instead. Splinters are a new type of currency that will drop from mobs more frequently than hero tokens did and can be saved up to purchase the hero of the player's choice. They'll also be used to purchase ultimate power upgrades and hero respecs.
Brevik says that the team is committed to adding new heroes to the game so that players will always have something new to earn. He also posted a FAQ regarding the upcoming system for those who have specific questions.