BioWare has confirmed Advanced Classes for the Jedi Knight as Guardian and Sentinel.
Here's the blurb:
Whether you want to defend the weak and inspire your allies to amazing feats as a Guardian or learn the art of using two Lightsabers simultaneously to create an intricate web of damage as a Sentinel, the Advanced Class system in The Old Republic will help you customize your character.
Bio's also updated the Biography section with Astromech T7-01.
Check out the Jedi class screens below, along with the video.
Game's out next spring.