It would be kind of fun if the template is a dark haired boy who is unusually strong in the Force and Obi-wan wants to train him but he is denied because he already has an apprentice but he trains him secretly anyway.
This will create a false Vader to distract the first time viewer away from Anakin (especially if little Anakin is not going to be the adjusted prequels).
He could turn out to be the brave Jedi shot by the clones before Bail's eyes at the temple.