i had long time ago a phd inteview (which was successful, but at the end i didn't go there... it was not in business though)...
- a general background warm up questions (about 3-4 minutes...).
- questions dealing with why phd in general and what i'm interested in doing (3-4 minutes as well)
- closing on my interests... what made me look at this direction, what do i know about it... including a very specific question "did you read XYZ book?" which i had to answer i have never heard of it.
- hypothetical questions about possible research. mainly methodological questions... "how would you search for....", "why do you think it'll work"... and the killer question "what would you do if you don't find anything..."
- back to nice and general topics... "why ABC school?", "general career goals"...
i guess that every interviewer will have his/her own agenda... but that's what i had and it seems generic (and frightening) enough.
at least this time i'm ready with all the right methodological answers
good luck...