There are alot of schools that are attempting to convert from a BS to a masters lately. Many are offering recent grads. the option of a masters with very little extra (maybe one semester). The difference in medical knowledge is almost non-existant between the two degrees. The extra classes will be in research/epidemiology/and courses like "health care for the poor" Worth getting the degree because some hospitals slot your salary, but it wont help you much clinically.
Oh, in case your wondering how -- and this is kinda cheating--but they actually go back and change the numbers on classes to accomodate the degree. Micro 404 majically becomes micro 505 on your transcript! I was shocked, but I was told schools do it all the time.