Announced at PSX
As a "one more thing" before he left the stage at PSX just moments ago, Sony boss Shuhei Yoshida confirmed that Raven will be playable in Gravity Rush 2 with her own little side story.
Previously she was confirmed as an AI-controlled entity, but Yoshida noted that because of fan demand, she will be playable. It's out in January 2017 so we'll find out soon enough for ourselves just how deep that rabbit hole goes!
It feels like I've been waiting forever for this game, but it's nearly here.