Lucasfilm has confirmed that Han Solo is getting his very own spinoff film, Star Wars Anthology: Rogue One, describing the story as focusing "on how young Han Solo became the smuggler, thief, and scoundrel whom Luke Skyawlker and Obi-Wan Kenobi first encountered in the cantina on Mos Eisley."
While they revealed a good deal of information on the film (although a bit sparse on the details), they did not reveal who would be in the film besides Han Solo. Sources are making claims that Darth Vader will be in the film – to some extent.
Vader will not be the main antagonist of the film, but will be working working behind the scenes — essentially as a puppet master, having others do his bidding. The source of this rumor detailed that Vader would initially show up through a viewscreen or holo projection, but would not specify if Vader would appear in person on screen.