Ok, first I want to say that I am no expert. However, I have been both wait listed and accepted (go class of 2014!) at UConn so I have learned a lot about the school over my time applying.
From what I was told UConn is HUGE about your interview. Unlike some schools (Wash U etc.), if you're invited for an interview at UConn, then you made the academic cut. This means that your GPA/MCAT scores will most likely not limit you on the admissions decision, its your interview score. The interview is their chance to see if you fit the UConn personality. Overall, I'd say at least 80%, if not more of the students are by far the most laid back and down to earth people I have met. In addition, they are really passionate about medicine and just overall a person you'd be done talking to and say "wow, they are going to be good with patients and are passionate about practicing medicine." I did not, nor have not really sensed many gunners at UConn. Then again complete pass/fail does that to students.
Correct me if I'm wrong, but anyone's best chance at getting into UConn when you receive the interview is if they show a sincere passion for medicine, easy to get along with and overall just a friendly person. The problem is connecting with both your interviewers. My advice is if you feel an interview went bad/or prejudged you from the start, get a new interviewer (trust me, I know from personal experience). My number one advice for interviewing is practice with a lot of friends and really get comfortable doing it. It can really make/break your chances in getting in.
If you are to write a letter of update to get an interview, I would snail mail it (e-mail can have a huge delay). Use the AMSAR address or website address. I would strongly focus in the interview how you'd be a good fit for the school and how UConn is your top choice, and any meaningful updates. Overall, telling UConn that they are your number one choice is probably going to help the most. I was told by a dean at another medical school that letters of interest/intent go a long way. For those who are put on wait lists, sometimes those letters are what get you off. In your case, just the fact that you can strongly state how much you want to go to UConn is really saying something.
P.S: If you are put on the wait list, the letter of intent/meaningful update "may" work until you are ranked. I have been told that once the wait list is ranked, it's completely static.