My interview was with an adcom member via Webex (like Skype). The interviewer was very friendly and made the atmosphere relaxed and casual. He made it clear up front that the interview was blind. After that we went right into the following questions:

1. Walk me through your resume.
2. Tell me about a time you lead a team and someone was less motivated.
3. Tell me about a time you managed up.
4. Tell me about a time you persuaded someone/the team to do something.
5. Why now? Why Wharton?
6. Do you have anything else to let me know about yourself?
7. Do you have any questions for me?

I thought the interview was very professional. The total time was about 25 to 30 minutes.