The latest casting choices have been made public for The Lightning Thief movie: Jake Abel will play the part of Luke, and Catherine Keener will play Sally Jackson, Percy's mom. I think both of these are excellent choices. Abel fits my picture of Luke almost perfectly, and that's not easy to do. And Keener will make a great Sally.
More news as it becomes available. Filming is underway in Vancouver and I'm hoping to visit the set when I'm there for my signing on May 7.