BioWare is aware of low framerate issues for some players of Star Wars: The Old Republic, and working on a permanent solution. Complaints from fans served as the basis of the team's investigation, and they've come up with a short-term fix while they work on the bug.
The response (via Eurogamer) to fan complaints promise more detail soon, but for the time being BioWare suggests closing background applications, turning down the graphics settings, turning off "bloom" in the graphics options, changing settings to favor performance over visuals, and updating your drivers.
It's not much, but it's a start until BioWare offers an official patch. "Our development team and our production team have been investigating this issue and we want to thank everyone who has posted constructively on this thread," the reply states. "You've provided the development team with a basis for investigation into the low FPS issues, and with your help they have identified and are in the process of resolving the indoor framerate drop."