Good Luck to all the R2 interviewees!
The most helpful (and calming) advice I had was from a current RC student. He said they test the following three areas during the interview:
1. Can you speak English well enough to succeed with the case method?
2. Did you lie on your application? They will probe your essays for detail. If you told the truth, you have nothing to worry about here. Just re-read your essays and refresh your memory with the details.
3. Can you pass an 'airplane test'? In other words, if the interviewer were stuck next to you on a long flight, would he/she be happy to chat with you for hours? My advice here is to be yourself. Don't be arrogant or pretentious. Be friendly, personable, down-to-earth and respectful. Shower
If you read back to the posts from R1, you'll find that almost everyone reported that their interviewers were really nice!