In an interesting study (particularly with the news about Sanford), researchers found that usually infidelity does not result in a divorce. Moreover, for a number of reasons (like folks waiting longer to marry) the divorce rate is actually falling.
“Despite strong social riptides working against it — the liberalization of divorce laws, the vanishing stigma of divorce, the continual online temptations of social sites like MySpace or Facebook — the marriage bond is far stronger in 21st-century America than many may assume. Infidelity is one of the most common reasons cited by people who divorce. But surveys find the majority of people who discover a cheating spouse remain married to that person for years afterward. Many millions more shrug off, or work through, strong suspicions or evidence of infidelity. And recent trends in marriage suggest that the institution itself has become more resilient in recent years, not less so.”