Well fallen are pretty much out of the picture, with Kell of Kells out of the way. Hive still have four deities, Eir, Yul, Xol and Ur. Vex, who knows. And Cabal we know there's something big right outside the solar system giving them orders regarding the dreadnaught. I'm sure we'll be introduced to more races, both bad and good, over the next 9 years.