I can't say under the new system, but under the old system (2010) the interview was very relaxed and quite informal. I would say that it was probably the funnest interview I have ever had. The interviewer was an RPCV, so they understood where I was coming from- the nerves, anticipation etc. It felt more like a conversation than a list of questions, and I was really excited throughout the entire interview.
Things you should definitely expect to talk about:
- How you plan to cope with living in a foreign country. Stress relief, examples of past determination when you felt like quitting.
- How you plan to keep in contact with people living back home. (The 3rd goal of peace corps is to promote understanding of foreign cultures by americans- if you can slide in some concrete 3rd goal activities into your interview- like a friend of yours is a teacher and you already plan to set up a penpal program with their classes, or you plan to send back monthly updates to your community center or church etc, that would be good)
- what you plan to do in your sector (this does not have to be very detailed, but for example, I was youth development and I knew I would want to do a lot of outdoor activities/camps/wilderness training with youth in my host country because that was the majority of my experience).
- examples of your flexibility
- examples of working with others --- how you plan to get along with your hosts.