According to Schmoes Know, they’ve picked up the following casting notice:
Storyline: Two 17 year old twins, a girl and a boy, are trained by their uncle Luke to be the greatest Jedi’s in the galaxy. Problems arise when the male twin turns to the dark side.
Jaina Solo – Female, 17 years old, lead. – Jacen’s twin sister, one of the greatest Jedi’s in the galaxy, trained by her uncle Luke Skywalker
Jacen Solo – Male, 17 years old, lead – Jaina’s twin brother, one of the greatest Jedi’s in the world. A loner who is constantly struggling with the idea of what’s right and what’s wrong. Starts to turn to the dark side. Full of conviction that what he is doing is the “right thing”. Will eventually become Darth Caedus.
So, basically, if this rumor is to be believed, they are taking the post-Jedi novels and making a movie about of them? I sort of doubt that, I’m not putting much stock in this rumor myself.