I cant wait until I write my withdraw letters:
Dear Members of the Admissions Committee;
I regret to inform you that my application should no longer be under consideration. This does not reflect that I feel that your medical school is unqualified in training individuals to become excellent physicians, it simply reflects the intense competition in gaining my matriculation. Out of the 125 medical schools in the nation, unfortunately, I can only attend one. Although the selection in so large, please be assured that your school has been given adequate consideration.
I am sure that your institution will succeed in training those bound for field of medicine. I appreciate your interest in me and wish your medical school well in its future endeavors.
Sincerely,
-me
AMCAS #111111111
This would be more appropriate to schools that havent gotten back to you about an interview (or waitlisted you although you are more than qualified to attend) than the ones that have already accepted you..... but it would be fun either way.