I graduated from a BS/MD program and am beginning to participate now in faculty interviews. The test scores, GPA, and extracirriculars are important to a point, but they can only take you so far. They get you that important interview. At our school, everyone starts the interview process with a blank slate. If you are number 400 of those we interview, you are the same as the number 1 person on interview day. Admissions are based on evaluations during the interview process. There are many exceptionally bright people who apply to these programs, however, the ability to remember facts and perform well on tests are not the only traits which make you successful in medicine.
In order to become an excellent doctor, you must have determination, commitment to serve others above self, responsibility, maturity, empathy, compassion, and dedication. It doesn't hurt to be a good listner and personable also. It is difficult to judge these characteristics in one interview, but that is what the process is set up to do.
You will find if you choose to pursue medicine, that everyone admitted to medical school is exceptional. Everyone in your class will have scores, GPA's, and extracirriculars the likes of above, but it takes a great deal of maturity and insight to get used to the psychology of being an "average medical student" when you have been exceptional in everything you have done in your life up to this point.