The supplement I have been working on has been sent to the editors for final draft. Hopefully it wont be too long before an editor is assigned and start working on it. At least two other projects are ahead of me in line though.
Template Toolkit: Spirits changed a fair amount from my initial draft and may change again before final publication.
It originally was built around templates, lenses, and prebuilt powers. The goal was for a GM to be able to just add up various packages to have a new spirit. Playtesters found that too complicated (there were a LOT of prebuilt abilities and lenses) so I thinned it down and went more towards the approach of GURPS Powers than Template Toolkit Characters or Races.
It still has lots of templates, a healthy amount of lenses, and plenty of prebuilt abilities. The main difference though is in building power sets and referring to those in GURPS Powers and GURPS Horror the GM has an inspirational list to work from. Many abilities are really simple and this change is easier to read and use.
I do not know what it will look like when its through editing but I am proud of this supplement and hope a lot of people get good use out of it.
Besides abilities for spirits it also goes into detail on various advantages to answer questions I have seen come up in games and on the forums. That material can be useful for games without spirits as well.