I saw this on Steam today:

http://store.steampowered.com/app/492680/

I don't know if GOG is already testing a build or if they don't even know it exists yet. But I figured I'd mention it now either way.

Looks great but I don't know if I have it in me to play through it again just to see some new walls and some wine bottles. :P

Waiting for this one here and the new update to 1.3 version.
Could take a bit of time though.
From the comments on Steam it looks like some platforms are not supporting the update or DLC.
Better let GOG test it through than get a black screen after update.

Created a wish for this DLC: http://www.gog.com/wishlist/games/craft_the_world_sisters_in_arms_dlc

And the DLC is here :)