As of this moment everyone is unable to apply for anything over Jounin. And if we get nothing -but- Jounin then we'll be lowering to nothing more then Genin. The main reasons we are doing this is because if everyone is amazingly powerful no one will have anything to do to increase your skills. This also allows the jounin to do stuff with squads and for me to hold Chuunin Exams and other such things. This doesn't count towards anyone who has already applied, ala those already posted.
Edit: Raikage and Kazekage positions are still open and able to be tried out for.