Writing is surprisingly difficult at the moment.
Roughly the shape of things to come is the following cycle of weeks per month.
Monster of the Month
Miscellaneous
Mythic Cheshire
Merceria Vendors.
I'm still not clear on how the Cheshire stuff will shake out as a final piece. It might be as short as a magazine article, or as big the Cornwall thing became.
As to the next volume of Ars Magica Monsters, I assume it'll be shorter than the 100 in the first volume. I need to decide if I'm going to have a mixture of creatures or a theme. If I do have a theme the most material is available for ghosts and reveners.