Well, not quite yet. Suppose in addition to simply lip-synching dialog, your characters must express some emotion. You want them to be able to say things sadly, or speak cheerfully. We need to add an emotional component to the system. At first glance, it may seem that you can simply add some additional morph targets for the base emotions.
Most people describe six basic emotions.
Here they are with some of their traits. Mouth smiles open or closed, cheeks puff, eyes narrow. Mouth cornsers pull down, brows incline, upper eyelids droop. Brows raise up and arch, upper eyelids raise, jaw drops. Brows raise and draw together, upper eyelids raise, lower eyelids tense upwards, jaw drops, mouth corners go out and down.