If you or someone else want to run with this, we can easily add a new tag for the occasion -- maybe "type: secondary character discussion" or similar? :-)

Other thoughts: I don't think it would have to involve a great deal of preparation. You could look on it more as crowd-sourcing meta -- invite people to discuss the character(of the week?)'s personality, arc, favourite moments and scenes. Maybe invite fanwork and meta recs too (incl self-recs)?

If no one person wants to run it, we could see if there's enough interest for different people to post for each character...

/random suggestions and ideas from pre-breakfast me :-)