Thanks, I_heart_fieldwork....hmmm, this is turning out to be very interesting. I guess there is the possibility that my advisor was wrong or misunderstood... After I got my interviews @ Emory & Northwestern, she called a colleague of hers and was under the impression that interviews had already happened (her friend's students had "talked to potential students" apparently, but I am wondering if there was a breakdown in communication...). HOWEVER, I would think that this would be definitely something the secretary would have told you when you made contact...I will encourage my S.O. to send an e-mail to her potential advisor and see what's up so we can compare notes...maybe my advisor is confused between flying in for an interview and just flying you in to show you the program or something? I'll see what I can find out and post an update...for your and my SO's sanity!
This also makes sense with others getting rejections and us not -- the pattern of operation, anyway.
I'll let you know what I find out! I might shoot some e-mails to a few people there, too.