The figure mentioned in there of two million Muslims converting each year appears pretty incredible to me, as in one should not believe it. After a bit of digging I think the number is way too high.
That having been said, Muslims are turning to Christ in Indonesia in significant numbers, we are talking about tens or perhaps hundreds of thousands per year. Time Magazine has a good article from 2010 about this, authored by Temang Gung and Hannah Beech (my favorite writer for Time who looks like she's twelve :-)
The article is titled Christianity's Surge in Indonesia and you can read it all HERE. For now, here is one section about this surprising growth and also the persecution that comes along with a vibrant, bold, growing faith.
What is it about Evangelical Christianity that has so resonated in Indonesia? As in many other crowded, developing-world countries where a person can feel lost in a teeming slum, the concept of individual salvation is a powerful one. At the same time, the attempted hijacking of Muslim theology by a small band of homegrown terrorists who have killed hundreds of Indonesians in recent years has led some to question their nation's majority faith. So, too, has the general trend toward a more conservative Islam that has given rise to hundreds of religiously inspired bylaws, from caning for beer-drinking to enforced dress codes for women.