ATMachine said:
One thing I failed to note earlier is the matter of the Emperor's makeup. As originally designed, it was meant to suggest extreme age, of such a span that it could only have been achieved through some unknown dark sorcery. The Emperor is described as "a Methuselah figure" who is "ancient, not old." In fact he's so old that he is beginning to evolve into something else--the ridge on his forehead is a point where his cranium is beginning to split in two. (And, unlike in ROTS, Ian McDiarmid was made bald up to the crown of his head, where the prosthetics stopped abruptly.)
I prefer the idea the EU originally proposed - that Palpatine was actually a lot younger than he looked, but that his immersion into the dark side had caused his body to wear out and age at an accelerated rate.
Still, it's a good idea in its own right, and far, far better than the moronic "scarred-by-my-own-lightning" approach of ROTS.