What should I write to my interviewer after being waitlisted?

May 5, 2009
I was recently waitlisted at UPenn and am in the process of writing one of my interviewers an email. So far, I've reminded him of the interview (in a polite way), and expressed to him that I was waitlisted, and thanked him for helping me get this far.

I have told him UPenn is my number 1 school, and that I really hope to be accepted. I then go on to let him know I intend to update my file, and that if he had any advice for me I would really like to hear it.

I didn't enumerate why I wanted to go to UPenn, should I do that? Also, is there anything I shouldn't do? Is there anything I should do that I haven't?

Any advice?