There is a lot of uncertainty with which direction the new Star Wars trilogy and spin offs will go. It is rumored, however, that a Boba Fett movie may be in the works, but nothing has been legitimately confirmed at this point, and it has also been heavily rumored that the new trilogy will be based off of the Thrawn Trilogy. For those who do not know, the Thrawn Trilogy is perhaps the most popular Star Wars spin off trilogy, and it takes place immediately after the Return of the Jedi. Despite all of the rumors and speculation surrounding the new trilogy, I do think one thing is for certain, besides having C3PO and R2D2. I have no insider information to base this own, but I am willing to wager a lot of money that Darth Vader will appear at some point.
Regardless if he gets his own spin offs or is involved in the main story line ( episode VII-IX), we will see Darth Vader, and a good amount of him, and not a redeemed Anakin Skywalker, but an evil Darth Vader. He is by far the most popular character from the franchise, and Disney didn’t spend north of $4 billion just to leave him out and keep him of the shelf. Disney, just like any studio, is a money making machine, and in a simple equation Darth Vader = more profits than anyone else. Also, there may not be an appeal for the average non star wars nerd to go see the movie without Darth Vader. Don’t give me the whole he wasn’t in the prequels, because the only draw the prequels had was Anakin eventually turning into Darth Vader. Now the question is how will they involve him? Well certainly if he were to get his own spin offs, you could easily tell stories of him before A New Hope began, but I honestly do not know how you can plug him into the main story line, but I am sure JJ Abrams and Disney will find a way.