I honestly wouldn't be surprised if we didn't see new cult troops at all. It would all depend on how well this book sells, and if it sells well, then GW might consider updating the Khorne Berzerkers.
But here's where they messed up. They made a book with no psychic powers that's focused on assault in an edition where psychic powers break the game and assault is the weakest link of the game. They also made it for Chaos Marines, which has some of the most jaded players out there at this point.
The only way I can see this working is if some crazy set of formation rules and that Strength D Bloodthirster make some top-3 tourney-winning combo when allied with a Belakor or something.
Then, maybe three years from now, we'll get a new Khorne Berzerker box.