The newest update to the Star Wars: The Old Republic site is a video that takes a look at how the team designed the classes that embrace the Dark Side: the Sith Inquisitor and Sith Warrior. According to writer Neil Pollner, the two themes that they wanted to explore with the classes are "domination and power."

The reason the team went with two Sith classes was to embrace the two archetypes that are embodied by Darth Vader and the Emperor. Darth Vader is a fighter, while the Emperor is a twisted, evil sorcerer. You can find out more about both classes by watching Developer Dispatch: Designing the Dark Side.