If you’re not excited about the idea of more Star Wars movies a year than there used to be in a decade for the foreseeable future then you need to get with the programme; Disney have spent more money than you’ll ever see on Lucasfilm and they’re going to do their darndest to make it a smart investment. So, after Star Wars: The Force Awakens later this year, there’ll be Star Wars: Rogue One in December 2016, and Episode VIII only five months after in May 2017.
The only person cast in the post-VII movies is Felicity Jones, who is the (presumed) lead of Gareth Edwards’ Rogue One. What the film will actually deal with is firmly in the realm of speculation – Rogue Squadron was prominent in the Expanded Universe, but now that’s non-canon it’s unlikely anything from those stories will be used – and the same goes for Jones’ role.
The originally stated plan for the non-Episode Star Wars spin-offs was that they’d expand on the origins of already established characters, meaning probably she’s someone we’ve met before, but even in a franchise as un-female friendly as Star Wars that’s not giving much away.
Who She Could Be Playing? Leia seems the obvious bet given the time frame (rumours are it’ll deal with the stealing of the Death Star plans), although Rebel leader Mon Mothma would make for a more expansive lead.