Yes we are actually working on this book now. It will be basically four sections: historical villains from the 15th Century, with brief historical biographies as well as stat blocks; generic NPCs as bad guys, foils etc with shorter descriptions and stat blocks (similar to the ones in Monsterberg and our other adventure modules); animals with stat blocks; and mythological creatures, spirits, beasts and monsters from Central Europe, with short descriptions and stat blocks.
It will probably be released this fall.