After exceeding many males in her training and after proving her loyalty during the Battle of Callos, Darth Vader promoted her to pilot the Rogue Shadow, a secret ship used to transport Vader's secret apprentice. From here she discovers who Starkiller is and they become romantically involved. Juno was also present at the birth of the Alliance to Restore the Republic and went on to become a pilot in the Rebel forces.
When the player picks the dark ending for Starkiller, he ends up killing Darth Vader. When Starkiller attacks the Emperor he ends up pulling the Rogue Shadow ship down on top of Starkiller, and kills Princess Leia, Kota, Bail Organa, and Juno Eclipse. This sends the Starkiller to the Emperor's side, making him half machine and half man, with all of his emotions locked away from him.
Force Unleashed 2
In the world premier trailer for Force Unleashed 2, Starkiller is seen walking down a hallway. He is then tormented by the voices of Master Yoda and Darth Vader. Starkiller begins to rip off pieces of metal off of the walls, until he hears the voice of Juno Eclipse. She says, "Will I ever see you again?" Which is what she said in the first game when Starkiller descended onto the Death Star. She might be in the video game, but it has not been announced.