I've finished the expanded information for the secret societies and am now working on new Edges!
EDIT: The Edges actually shouldn't take that long. I really, really dislike Edge bloat, so I'm limiting myself to 13 new Edges. I don't know if I'm going to bother with any new Hindrances; the existing core Hindrances can be easily tweaked to fit most concepts (and there's a section in The King is Dead's character creation about doing just that). After that will be a section on Arcane Backgrounds and their trappings and then some gear.
My biggest problem was that I just had a horrible case of writer's block when I got to the Zunft von Hohenheim. I kept writing them as borderline bad guys and had to force myself out of my post-atmic bomb anti-science prejudices and into the more progressive values of an earlier age. It was hard.