Dear all,
I'm looking as well for a way to batch edit aiff files on the Mac. I added a request some time ago on the Jaikoz wishlist: http://www.jthink.net/jaikozforum/posts/list/1841.page
Paul Taylor, the Jaikoz developer, answered that it has been added to the "to do" list. If more of us would request the same feature, maybe it will move up on the priority list.
Ciao!
Willem