Haitians vote today in a much-anticipated presidential runoff amid concerns about the return of a former leader from exile. Former first lady Mirlande Manigat and popular entertainer Michel Martelly are competing in the second round of voting for the job of rebuilding a nation beset by deep poverty, an earthquake-shattered infrastructure and a cholera epidemic. International donors are waiting for a new government before they release billions of dollars of reconstruction aid. A U.N. spokesman said the world body is monitoring the situation in Haiti, saying the most important thing is to ensure a smooth and well-run election today. The winner of the runoff succeeds outgoing President Rene Preval.