According to the residency directors we heard talk last night at a class meeting, more and more residencies want to see your step 2 score. Apparently studies are showing that success on step 1 has practically no correlation to success in residency. However, those who score well on step 2 are much more likely to shine as residents.
The directors basically told us third years to take step 2 by October at the latest, because it takes 4-6 weeks for scores to get reported in ERAS. They also said it's a good idea to do your sub-I or EM rotation before taking step 2, because this will help reinforce what will be on the exam.