I'm dissapointed. Most people didn't even thought about what I said. I did not said Mace Windu was a Sith. I used the word "evil" meaning a corrupt Jedi, a Jedi with ambition, with politic interests.
Yoda said something regarding the Jedi being corrupted. I'm not sure where, but he said so.
If you guys just see the movie with what I said in mind, you'll totally see Mace Windu's game in his acting and words.
- Having Anakin to stay and promising him something that could be read as "be good and don't poke your nose on this. If you stay I'll remember you when I become really powerful".
- Entering with three Jedi and announcing: "You are under arrest", like if he didn't already know Palpatine was a man of influence.
- Showing anger during the fight.
- Having the "heck, now there is an eye witness!" face when Anakin appeared.
- Choosing to kill Palpatine eitherway.
At this point, when Palpatine is burning his face with his own electricity to avoid being killed, Anakin does not have "pure good" vs "pure evil" in front of him, but the relative morality Palpatine was telling him about. Two half truths is what he sees; both were evil, which makes Anakin's choice more rational.
Now, some of you are saying that George Lucas did not say anything about that, therefore it's not official, well. I have two things to say:
1) Characters sometimes escape the author's intention to become something else. See Han Solo, for example. He was an independent greedy guy... and someone who did not hesitate in killing in cold blood to protect his integrity. Later on, George Lucas realized the character was a little bit different of what he intended and wanted to change it but it was too late, for he already belongs to the fans.
2) Sometimes the author of a story wont tell you his future plans, and if you are guessing, he is capable of denying the whole thing. An example of this would be J. J. Abrahams with the second Star Trek villain. We know George was interested in using Mace Windu in the future, and now we know there is this spin off.
People, don't be so quick at disregarding this analysis. Go see the movie. Even the laser saber matches the story, and you cannot tell for sure if the color was intended before hand and the story you have of S.L.J demanding a pink saber was just a cover. Didn't Samuel J. say there was a secret in Ep3?