What is one of the specific questions they asked you?
Tell me about how you've come to be interested in a medical career. Why would you not pursue a degree in clinical psychology with your background? Why did you take the MCAT so late (non-traditional applicant) and what did you do between graduation and the test?
This web site, NYTimes health section, AMA website, mock interview (although none of these were really necessary).
What impressed you positively?
Exceptionally friendly students and staff, comfortable atmosphere.
What impressed you negatively?
The tour was too brief and conducted in a large group.
What did you wish you had known ahead of time?
That the day would be virtually stress free.
What are your general comments?
Don't stress about this for a minute. The interview questions are obviously very important, but at least in my case, they were presented in such a way that you could not be anything but yourself. The interview was conversational, almost disarming. Great day overall, it will probably move Penn State up on your list.