I think it just depends on the school. At my last interview they told us we had a 50% chance of being accepted...so half of the people there probably won't get in. But if you got an interview, then at least you still have a chance!
I know a lot of people who were interviewed and were never accepted. The most common situation seems to be waitlisted and never called for a spot. I think it does depend on the school (i.e how many interviews they do vs how many spots). Although if you were a horrible canidate on paper, they would never interview you.