Sudan is less than six months away from a seminal event: the referendum on whether Southern Sudan remains part of a united Sudan or secedes. In an effort to stimulate discussion of and planning for the referendum and its aftermath, last year the United States Institute of Peace and the Netherlands Institute of International Relations Clingendael each conducted scenario development exercises designed to describe a few of the potential scenarios in Sudan surrounding the referendum. One year later, those scenarios are being revisited to evaluate how they have held up and which ones appear most likely given recent developments in Sudan.