Well, this is something none of us saw coming...
Telltale have announced that they're going to make a new game, based off another popular game. That game? Minecraft.
It'll be an adventure game and it's called Minecraft: Story Mode. Despite the name though, this is a stand-alone title, not a new game mode being added to Minecraft. It's also going to follow in the tradition of other Telltale games such as The Walking Dead and Wolf Among Us in that it will be episodic. Right now they are collaborating with Mojang and the Minecraft community in an attempt to make it as Minecrafty as possible. Telltale say that it will premier in 2015 for consoles, computers and mobile.
Mojang themselves have spoken about the game, saying it will not be an adventure for long-standing default avatar 'Steve' (or we assume 'Alex' the other default added in 1.8) nor will it go into details about the world of Minecraft itself.