Kanos has great potential, always has. Ventress is a moderately important player in the Clone Wars. Illum Padmé is an...interesting choice. I'm indifferent to Thrawn, and can hardly stand Mara Jade.
In the end, for me it will come down to Vos and Illum Padmé. I see Vos getting my vote for several reasons, one of which is that I simply liked the character of Padmé so much better as Queen and later Senator than when she was relegated to the "hot gun-toting chick" role.
An Illum version of Padmé might be nice some time down the road, but for now, I'd like some rather unknown characters to be given a chance. Vos has proven to be a true standout in the EU, and hopefully, even if he does not win, SSC will notice the interest in his character.