Kathleen Kennedy (essentially) has the final call on all things related to star wars movies.
IMO, JJ did a good job getting the new story off the ground, while ignoring much of the prequels.
Design wise, I'm not a huge fan of the FO Stormtrooper armor, Kylo Ren is pretty cool in an unstable kinda way. Love that JJ went back to actual locations and used real sets, locations and props for most of the TFA.
The second movie is the pivot, much like ESB - that'll be very telling in where Disney decides to take this particular trilogy.
I do hope they expand on the "spin off" movies. I'd love to see a trilogy about the smuggler side of Han Solo, seeing his relationship with Jabba fall apart, and basically lead right up until he meets with Luke and Obi wan at the Cantina.
In a similar vein, I'd have loved to see Rogue One, ignoring the entire prequel disaster, made into a Trilogy leading right up the opening chase of ANH. That'd have been pretty slick and worth of a true prequel.
They could do this with Boba Fett - or blend him into the Han Solo movie. Not sure if he'd be a good lead character, though.