Lucas may have been trying to set up Palpatine as one of these Changlings, but opted instead for the "Mace augments his own Force lightning against him" scenario. I don't think he had any idea how to handle Palps' transformation, and may've been trying to set a precendent for it with this character. Who knows really?
In any case, it was dumb, and TM is right for cutting it out completely.
--ID