So I have been working on setting up a joint based muscle face rig system. It is coming along nicely, and I showed it to a work mate yesterday and he was blown away and said I've gotta post the work. You can see a little bit of it in my reel here: Showreel, but I will record a detailed screen grab of the rig working and post it up to show off the deformation and skin sliding that I have set up. I have set up a very cool sticky lip system as well as some nice soft eyes and muscles that slide over the surface of the underlying skeleton to preserve volume and create some nice skin sliding effects.
Finally I am doing a dynamics pass to get some jiggle in the looser neck skin, and I think I will do a final hi-res render mesh that I may sculpt some wrinkles on to be driven by the muscles so I end up with a nice overall package. The final result will hopefully be a rendered greyscale pass with some nice lighting to show off the deformation.
I'm going to try for an initial post of the rig in progress in few days by the time I record and upload it.