Clearly it's a very complex topic, but generally speaking, I do believe that Haidt's recent work is more or less on the right track in this regard.

That said, much of his insight is not very original, and can be found in the work of other, often much older thinkers, some of whom Haidt cites. Haidt's significance is mainly that he's trying to pull off a "Nixon in China," i.e. to leverage his own liberal beliefs and credentials to formulate these insights in a way that's palatable to liberals, who would be instantly repulsed and incensed by the other authors who have presented them previously. (I'm not very optimistic about his chances, though, especially since he has to dance around some third-rail issues that might destroy his reputation instantly. Similar can be said for other modern authors who delve into social theory based on evolutionary insight, like e.g. Geoffrey Miller.)

Also, I think there are many other crucial pieces of the puzzle that Haidt is still missing completely, so he still strikes me as very naive on some issues. (For example, I don't know if he's familiar with the concept of Schelling points, but he definitely fails to recognize them on some issues where they are crucial. He also apparently fails to grasp what virtue ethics is about.)