DS has been on "Hold" for two months, and his letter in late March confirmed that he has "been placed on the national waiting list as a Hold Candidate." But then it gives a further interesting wrinkle: "As vacancies occur, Hold Candidates are offered appointments in order of merit, based upon their competitive standing on the state and national listings." So both your standing in your state and your standing nationally come into play. If several people in your state turn down their appointment, you could get an appointment if you were ranked high enough in your state, even if your national ranking was pretty far down the list.
Good luck to everyone still waiting!