The upcoming shutdown, taking place on December 15, 2011, will put an end to both the MMO and Trading Card Game, which was an aspect of the game released as a part of an update in 2008. The official site describes it as a "very difficult decision, but SOE and LucasArts have mutually agreed that the end of 2011 is the appropriate time to end the game."
"We are extremely grateful to all of the SWG fans. We have had the rare opportunity to host one of the most dedicated and passionate online gaming communities and we truly appreciate the support we've received from each and every one of you over the course of the past eight years."
This used to be the greatest sandbox MMO ever created until it was ruined by the New Game Experience (Enhancement) (NGE) - after which a LOT of player quit due to the extreme casualization of the game and simplification of all mechanics to cater to the, at that time, new competition - WoW.
This is also a sign that SWTOR is coming on the way! So get excited!