In a completely left field announcement, Mojang have announced that they have partnered with Telltale Games to bring a narrative driven Minecraft experience, called Minecraft: Story Mode, to all devices under the sun sometime in 2015.
As seems to be the case with most Telltale games, Minecraft: Story Mode will be an episodic affair, with new episodes of this blocky story coming out every couple of months. As for the actual tale itself, it will be a stand alone product from Minecraft, driven by player choice and partially based on the mythos that Minecraft fans have constructed around the game. Expect Herobrine to pop up somewhere.
Expect more news on this curious announcement in the new year.