Parents being divorced seems to be an ever growing concern for many of my brides and grooms. Should your step father walk you down the isle instead of your biological father? Is the father of the groom remarried and his mother isn't? How should they be introduced into the reception?
These are some questions that I deal with regularly. Some families are well adjusted while others are still dealing with the sting of the divorce. Each situation is very different and very personal. The best thing that you can do is make your vendors aware of any situations ahead of time. You do not want the photographer to miss-step asking the exes to hold hands and get close in shots when they each have new significant others. You also do not want the DJ to refer to them as Mr & Mrs if they no longer are.
Just know these situations are very easily handled, however, communication is key. The more that you can convey to your professionals, the better the evening will go.