What I'm really curious about is whether they are "official" interviews that are now a formal step in their admissions process, or if it is a more informal/ad hoc inquiry from a potential advisor who wants to learn more - e.g. does not being invited to interview constitute a rejection? What about in cases like my husband's, where he was just up at Princeton last week to meet with their Eurasian specialist - should he still be hoping for an interview request, or would that discussion "count" retroactively?
Unfortunately, there just isn't enough forum action in my field (global health policy), so I'm channeling all of my nervious energy into worrying about his...