The other day I got an idea for a companion character mod that would make for a fairly non-standard follower... The idea was for a healer (possibly priestess or maybe even a Sybil of Debella) who is a healer and a pacifist. She would heal you in battle but would refuse to participate in the fighting. She would also refuse to wear armor or carry a weapon. This would be a character with a positive outlook on life and of people, has a sunny disposition, is wise beyond her years, seems to know more than she lets on, and is sometimes frustratingly cryptic.
I also had an idea for a male follower (probably a Nord) who is a werewolf, bitter, synical, and jaded. He hates people and would refuse to go into town... maybe he would even refuse to stick around if you have other followers he doesn't know in your party. This is a much less developed character.
I have no intention of starting work on either of these any time soon because I am in the middle of working on two other fairly ambitious mods right now, but this is a project that I would like to stick on the back burner for now so there is some possibility I will start work on it eventually so I'm curious to hear what people think, or any suggestions they may have.