Just how do you achieve facial animation.
Just move some vertices around.
You could use Lattice or RVK’s to deform the verts in the parts of the face you want to animate:
Or you could use Armature bones:
Or you could use Hooks:
Or a combination of any number of them. In the upcomming version 2.40 RVK’s will be replaced with Shapes and shapes can be driven with IPO’s (animation curves) of other Objects or parts thereof so the possibilities increase and the choices narrow. Shapes or Bones. Study up on those 2 and you’ll be set to go.