Andrew Walden claims that Muslims are leaving Islam in droves, mainly for Christianity or secularism.
Pope Benedict’s choice to publicly baptize the most prominent Muslim in Italy, Egyptian-born Magdi Allam, highlights a quiet worldwide exodus from Islam. In recent years, millions have moved on. With this high-profile action, Pope Benedict demonstratively blesses this massive conversion from the highest levels of the Church. ...
Although al-Qataani points to Africa, there is another phenomenon based on repulsion from Islamist dictatorship, corruption, and terrorist violence. In Iran as many as 1 million people have surreptitiously converted to Evangelical Christianity in the last five years. Pastor Hormoz Shariat claims to have converted 50,000 of them through his U.S.-based Farsi-language satellite ministry. He contrasts the upswing to the efforts of evangelical missionaries in Iran between 1830 and 1979, whose 149 years of work built a Christian community of only 3,000.
Lots more there, with a great many links. Not sure how accurate the premise is as a whole, but it sounds encouraging.