Once, there was little doubt that becoming an MD was an amazingly attractive career choice. Physicians were paid well, highly respected and, for the most part, acted as their own bosses. But times have changed. College counselors report that as pre-med students finish their undergraduate degrees, a small but growing number of them are making a surprising choice. Rather than going on to medical school to become doctors, they’re heading to nursing graduate schools that will train them to become nurse practitioners. Financial and lifestyle issues in the healthcare industry are feeding the trend.