You should contact Antonietta Caccia at
circolo@zampogna.org, she will be able to give you the information you need (might take a week or two, but she will answer, and she has good English).
As I've been told, at the moment it looks very much like the "Rencontres" are coming back to St. Chartier rather than Château d'Ars. The festival committee has been reorganized, and contact has been made to the new owner of the castle who seems to be very keen to support the festival. There is a good chance the festival will be on in 2014.