Massachusetts has had mandated parent education for some years. The course is titled "Understanding the Effect of Divorce on Children" and more information can be found here (PDF).
I have always thought it was a good idea, not everyone gets it, of course, but I think many do. Simple civility and how to keep the kids out of the middle are a great idea for divorcing parents. A colleague sent me this article* which seems to indicate that these requirements have a beneficial effect.
I was also interested to see that the divorce rate is dropping.
*UPDATED 11/30/09: Link removed as article now blocked from public viewing by the AP.