Techland has announced The Following; an major DLC expansion for Dying Light which rivals the original game in size:

Today Techland has confirmed that it is indeed working on Dying Light: The Following – a feature-heavy, story-based expansion pack.

“For Dying Light: The Following we’re adding a number of bold game-changers to create one massive expansion. Something big that will give the game a brand-new flavor. The new map alone is the same size as all the previous maps from Dying Light combined, so there is a lot we’re packing in here.

We also kept a close eye on player feedback to help tailor what we’ve created here. Hopefully people will see that this new expansion is first and foremost, for the fans.” 
– Tymon Smektala, producer, Dying Light: The Following

Techland announced that Dying Light: The Following will be available for purchase separately but will also be made free to all Season Pass holders. The expansion pack is set to be showcased behind closed doors at Gamescom next month, with a full public reveal following shortly after.