Coruscant is a well known planet in the Star Wars Galaxy and capital of the Republic. It may be best remembered in the Star Wars: The Old Republic saga from the E3 trailer Deceived
featuring the sacking of Coruscant by the Sith. Bioware recently revealed more of the story and lore behind Coruscant on the official Star Wars: The Old Republic website's HoloNet feature.
Coruscant. A symbol of power, prosperity, and innovation for civilization. The capital of the Republic serves as a hub of cultural influence and home to hundreds of alien species and from across the galaxy. Still recovering from the Sith attack during the Sacking of Coruscant, the planet has set out to rebuild what they have lost. Though the pristine skyline continues to grow, the lower level districts of Coruscant have developed troubles of their own.
Read more about Coruscant here
(via tentonhammer, thx!)