Via Ign.com:

In a trailer released recently,  Bioware teased the return of Revan in Star Wars: The Old Republic. Revan originally appeared as the amnesia-ridden protagonist of Star Wars: Knights of The Old Republic for the original Xbox. He wouldn’t be seen again for some time, with only some brief appearances in theStar Wars: The Old Republic MMORPG for PC, most notably a mid-level Flashpoint (an instance-based, short adventure for four people). This new trailer shines a light on him however, which leads us to believe he will play a major role in the upcoming 3.0 update for the game. This is only the beginning of what will be the 3.0 content update for Star Wars: The Old Republic. Last week we reported that they would have a full announcement by the end of September, detailing the upcoming expansion.