Josh Jackson was recently in Bobby, also auditioned for Batman Begins but was obviously unsuccessful. He's attached to other projects, Fletcher/Fletch Won is the only one I can think of.
James Van Der Beek was in Ugly Betty recently, or will be in Ugly Betty, I saw pictures of him on the set floating around.
Michelle Williams was going to play the Charlotte role in Bronte, which after some initial hesitation I was looking forward to, but she had to withdraw because of scheduling conflicts.
Katie Holmes we all know what happened to her, and Kerr Smith ... *shrug*
The only one I never, ever see is Meredith Monroe.
The Scream and American Pie gang I've no idea.