According to a Boston.com article a woman in Ohio learned via Facebook that her Husband had re-married, despite still being married to her. While the article suggests that there is some disagreement about whether or not the original marriage was valid, it's clear that the Husband should have waited to have the validity of his first marriage determined prior to getting married again. He has risked having his second marriage void, if the first is found to be valid.
This situation is not typical because most clients seeking to end a marriage state that they are not in a rush to get married again. However, according to the U.S. Census Bureau between 66 and 75% of people who get divorced get remarried. Many of these remarriages are less than one year after the divorce.
At the very least you are required to wait to get remarried until the day when you are officially divorced. In Massachusetts there is a waiting period (90 days for Complaints for Divorce, and 120 days for Joint Petitions) until a Divorce becomes final after the hearing. A Judgment of Divorce Nisi does not become absolute until 90 days later, and you are therefore technically still married during that waiting period. If you want your second marriage to be valid you must wait at least that long before getting remarried.
Although this may seem like an unusual problem, since many couples are now choosing long-term separation over divorce, the eventual divorce may occur well after the marriage has practically ended. In fact, the new relationship is more often the impetus behind the ending of a long-term separation. For a discussion on the other issues raised by long-term separation vs. divorce check out our previous post.