We finally have confirmation for Game Update 1.7: Return of the Gree going live on servers Tuesday, February 12th with no PTS scheduled for it.
Quote from BioWare CS
Hello everyone, we wanted to let you know that we will be performing scheduled maintenance for five and a half hours on Tuesday, February 12th, 2013 from 3:30AM CST (1:30AM PST/4:30AM EST/9:30AM GMT/10:30AM CET/8:30PM AEDT) until 9AM CST (7AM PST/10AM EST/3PM GMT/3PM CET/2AM AEDT). All game servers, SWTOR.com, and the launcher will be offline during this period. This maintenance is expected to take no more than five and a half hours, but could be extended.
Game Update 1.7: Return of the Gree unveils a new in-game event, Relics of the Gree. Travel to Ilum to investigate the appearance of an ancient Gree starships, called “the Gray Secant.” The Reputation System is also introduced in this game update, which allows you to earn Reputation points by completing missions for organizations such as the Gree or the Voss, or for military divisions within the Republic and the Empire for great rewards.
After this maintenance is over, restart the game launcher to patch to Game Update 1.7: Return of the Gree.
Events are available to Free-to-Play Players and Subscribers at no additional cost. Visit the Free-to-Play Features Chart for more information.
Once the patch is live, check back here for information and guides related to the update; I'll try to have them up as quick as possible.