I don't see Islam being around in six centuries. It's too empty and so lacking in God that it'll implode upon itself. I predict that I'll see it on the ash heap of history in my lifetime and the grandchildren of its most violent practictioners bowing down and proclaiming that Jesus Christ is Lord. Before you say I'm too "pie in the sky", consider:
-Ronald Reagan predicted that the Soviet Union would be on the ash heap of history, at a time when it looked the strongest.
-According to a Muslim imam, there's 6 million Arab Muslims converting to Christianity annually.
^million annual converts does not come near to offsetting the Moslem birthrate.