We just completed our Peace Corps interviews today! For couples, you must be interviewed individually, and then together. The entire process took about 3.5 hours (but we had lots of questions to ask our recruiter).
The individual interview questions were almost identical to those on the Peace Corps Wiki site:
http://www.peacecorpswiki.org/Interview_Questions
The couple interview questions came directly from the couple questionnaire (See previous post).
Our recruiter told us we will probably be nominated within the next couple of weeks. Then on to the medical review!