hmmm yeah I've always been kinda intimidated by Terranim8or so I never really looked into it. But maybe I'll give it a look later.
I was hoping for a low poly solution since I havent gotten a handle on morph targets yet. Realism wasnt much of a concern, I'll probably end up just doing something anime styled anyway starting out...(...again)
EDIT:
Just a thought that occured to me, if you had a mesh with a certain texture then made a duplicate of it in the same place with a different texture and then hid it wouldn't that achieve the same thing? I mean you'd have to make sure you grabbed each head when ever you moved the bone unless you can parent both simultaneously but in theory it would mean that every time you hid one head the other would show with a different texture.
Now all that remains is to test it!.... tomarrow thought since it's 3 am...