Softbody stuff on steam looks really promising. I wonder if you can create a weight blending setup so that you get the volume and structure from bones, but allow all the jiggly bits where appropriate. Creating that surface tension would go a long way in keeping the weight, volume and believability. Painting influence in spots where the skeletal structure is closest to the surface. Not sure how you'd solve the exploding mesh/volume tension issues so it stays consistent. Very very nice work so far.