In TPM we learned more about the nature of the Sith- powerful individuals working invisibly in the background to bring back their old, evil ways. In AOTC, learn that the Sith control much of the senate and manipulate Corporate and Commerce guilds, and create wars to destabilize the the republic. They are interested in controlling the galaxy!
This reminds me of the old "Illuminati Conspiracy," a cabal of powermongers (or satanists, depending on what you read), who operated in the same way. The most fantastic version of the legend has them working for a new world order with themselves at the top, working over hundreds of years to secure the downfall of religions and the reintroduction of pagan practices. The Illuminati control banking and commerce institutions through blackmail and bribery, instigate wars, and infiltrate innocuous sects of society like the Freemasons in order to control the world!
I wonder if George had the Illuminati in the back of his mind when he was dreaming up the nature of the Sith? Maybe, maybe not. But I thought it was an interesting and fun comparison.
By the way, I do not really believe in the illuminati. What do you guys think?