This is such exciting news! My top guesses for playable character options are Ciri or Yennefer. Both characters play a large role in the Witcher saga and their abilities would lend well to unique forms of magical combat. Lambert is also featured in the trailer, but I don’t really see a reason to have players switch to another Witcher.
If you could play as another character in the Witcher 3, which character would you choose? Who knows, maybe we’ll get to play as Dandelion and wield some killer poetry. 😉