The latest rumor is that Ryan Gosling and Zac Efron were being considered for roles. But Gosling's people have since come out and denied his involvement.
Still don't know who they could possibly play? Maybe Jacen and Anakin (or maybe Ben depending on the time frame). Maybe Gavin Darklighter or Corran Horn.
Still don't know if they will take a story (or combo of stories) from the EU or something original.