I have TiVO so I let it record MTV for a little while, then rewound to one of the spots, then did a frame-by-frame. It's very possible it was done in Character Studio using Zygote figures, but I really think it was done in Poser. The spots go by so fast that you miss that the backgrounds are actually live action stills. It looks like the animations were rendered in Poser and then composited onto the background in such a way that it retained the shadows on the ground. The biggest evidence that it is Poser is the way that Posette's shoulder joints move in one of the scenes.