One interviewer focused mostly on going through my AMCAS in a lot of details. Asking questions about experiences I mentioned in my PS, asking for more details about my ECs, research, etc. I got the impression that he'd actually looked up a little bit about the organism I researched, so we were able to talk a lot about that...
My second interviewer was much more general... Why medicine? Why Hershey? Plans for the future? The basic interview questions you should be ready for....
Both interviewers asked me if I had questions for them several times, so make sure you think about that beforehand...
I should also say that although my first interviewer was asking very specific questions, I don't think the intent was to grill me, and it felt very laid back the whole time. I think he was just genuinely interested in the work I had done. A lot of the questions were also geared toward understanding why I'd gotten involved with certain activities and what I got out of them, so hopefully I didn't make that interview sound more intense than it was...
That said, make sure you know your AMCAS pretty thoroughly, be prepared for the typical med school interview general questions, and you will do well.
I really loved it at Hershey, so try and relax and have some fun while you're there. The students and faculty were exceptionally friendly and helpful. Make sure you eat a good breakfast though, because you can smell chocolate from the factory at Hershey Medical Center... Your stomach will definitely be growling by lunch otherwise!