Work in progress, just getting the basics/looping down right. The advantage will be posting a block of text in one frame and letting the script do much of the animation, then you can just draw over the top for areas where you want special graphics/lines in a layer above the mouth movie clip. IT also allows controlling facial expressions with the dialog by using numerical values. Press the blue button to see it in action. There are still tons of rules to write in, but the idea will eventually be to help individual animators with this time consuming part of the process. If the mouths/eyes are embedded in a face, it will also offer easy control through the "this" reference, which would then be just applied to every face instance for multiple uses within the same frame (you'd also want to do this so things can move together obviously).
http://coalminds.com/animation/lipsync_stage4.html