Let me just tell you what I think...
And you know, i don't really give a flying fart if this has been covered already in this here forum, because I don't have the time any more to just sit around reading this crap all day every day like I used to. So don't give me any grief, because if you do, it will be ignored, or I may just give you the old generic flame form
So, here's what I think:
I think George Lucas made a big old shite-eating mistake when he DIDN'T make Palpatine the apprentice who killed Darth Plagueis (I don't know how it's really spelled, and this is how I'm spelling it). He also made the stupidest goofiest mistake in the history of Star Wars movies (and there are lots of them to compare to) by making Palpatine's massively aged appearance a result of his using his lightning force power for a long time on Mace Windu. Stupid. Stupid. Stupid.
Let's face it here, Lucas missed a once-in-a-lifetime chance to write this story the way it should have been written. It is SOOOO PAINFULLY obvious how it should have happened. Let me elaborate:
Palpy is at that weird space water show with Anakin. He's stroking his ego and telling him about the sith. Then he goes into the story about Darth Plagueis and how he had the power to save lives, create life, and bring people back from the dead. He tells him how this was 1000 years ago. He tells him about how Plagueis was so short-sighted and stupid that he didn't realize that his apprentice was plotting to kill him in his sleep. Anakin's like "hmmm".
Ok, so we advance a bit and we're at the part where Windu is confronting Palpy. Palpy reveals to them that he is a sith and attacks them (we'll not mention what a LAME looking fight that was and how nobody in the production of the film seemed to care that McDiarmid looke completely stiff and nonconvincing in this fight). Anakin walks in and is all like "Hey, WTF? What's goin' on, yo?". And here's what SHOULD have happened:
Palpatine is on the floor, succumbed to Windu's superior light-saber skills, when we see Palpy suddenly grunting and groaning in horrible pain as he lets go of the control he has on his own body (using his very powerful control of the dark side of the force) which has been maintaining his body to give the illusion that he is a man in his 50's, when in fact he is over 1000 years old, frail, wrinkled, and hideous. THIS is when he would release his lightning force on Windu, hurling him out the window to his death, as the sight of Palpy transforming into this old man causes him to lose track of what he is doing.
So, it would turn out that Palpy was in fact the apprentice that killed Plagueis, and has spent all this time hiding his true self, waiting for the perfect time to use the dark side to take control of the galaxy. He also would have become so powerful in the dark side that he would have developed the ability to "create life" with the dark side of the force, and would have been the one who created Anakin from the force inside Anakin's mother, as a means to his control of the galaxy.
It's all so simple. It should have been this way. This would have been perfect. Anybody who really thinks about it knows that this is the way things should have turned out.