Changing Guidelines vs. Changing Practice

It's been a few weeks since an expert panel recommended that the guideline for mammography use be pushed back to age 50 (from age 40). During these few weeks, it was interesting to see how much controversy this understandably generated. As too much screening causes more harm than good, and the panel has demonstrated that this is the case for women in their 40s, physicians and patients alike have opposed the new recommendation and will continue to follow the old recommendation knowing that it only benefits 1 out of 1,900 women in their 40s. I think it's interesting and right in line with our discussion earlier this year on how people react to change. Of course, guidelines are just that, and they likely won't change physician practice in the short run since screenings are administered on many factors such as family history, etc. What about the long run, though?