Based on my interview experience (jan 17 2006 at Atlanta DO), they simply cross check some of the stuff u wrote on your N-400 application. For me, the Officer simply asked the following:
1. Has your martial status changed?
2. Did you travel last year?
3. What company do i work for and in what position?
After that the Officer asked the general questions have u been involved in any crime, worked against the government etc
After that, I was asked 3 questions straight from the 100 questions. Told me to write a sentence down which the Officer vocally expressed.
Thats it.. I signed my photos, Officer handed me my N-652 form, and said Congrulations u passed, Oath notice will be send to u
Hope that helps