I think that this teaches us that there is no thing as true good or true evil. We've been so caught up with taking sides, just assuming the Smoke Monster was pure evil. Obviously, the path that lead him to where he is today was actually an honest man's path. Maybe we shouldn't judge. There is no good or evil. Only the circumstances that lead us to where they are today.
The number one thing I took from this episode was that we always believed Jacob was right and all knowing. Now its safe to assume that Jacob may have been long conned by his mom.
Then again, Locke did just blow up an entire fucking submarine.