The American Association of Medical Colleges has released its Report on Industry Funding of Medical Education (PDF), the result of over 2 years of work.
There is lots of good discussion on this: Howard Brody, Daniel Carlat, Merrill Goozner, and, in detail, Roy Poses from Health Care Renewal.
Also, please be sure to check out the horrifying details related by Clin Psyc on the newest Paxil study. While it may be too much of a generalization to suggest that professionals in general do a poor job of self-regulation, the modern history of the medical profession (since 1847) should not inspire confidence. As someone sympathetic to virtue ethics, I believe quite strongly that the building of professional and virtuous character should be a paramount pedagogical goal for medical education. Yet, given the legacy of lax self-regulation, which, as CP notes, continues to this very day, it is becoming increasingly untenable to suggest that such self-regulation is sufficient to resolve the worst problems of scientific misconduct and conflicts of interest.