BioWare Producer Blaine Christine recently sat down for a Star Wars: The Old Republic interview with Steven Crews at The MMO Gamer. The interview hits on a number of facets of SWTOR's gameplay and the process of creating the title. They also discuss how BioWare is designing the game to dissuade everyone from (only) running around wielding lightsabers through the unique strengths of each class, but their talk really focuses on the game's story.
Blaine discusses how the story for SWTOR players, whether they choose to be good or evil, will always be more than kill ten rats or "collect ten boxes for some random vendor." That story you play through fits the role you've chosen for yourself. Blaine likens a player's story progression to Knights of the Old Republic. He tells The MMO Gamer, "If you look at KOTOR and how that worked out, if you played light side versus dark side, there were distinct differences in the story, and distinct differences in how your character developed. It's going to be very similar to that."