The Muslim world was in decline far before the Ottoman caliphate fell. It went into decline the moment it started looking towards the West as a source of inspiration. The latter Ottoman caliphs and their governments brought forth anti-Islamic laws and reinforced secularism. As for these revolutions that have happened in the Middle East, all we can do is wait and see. A lot of times, Western powers have been behind these revolutions and the replacement has usually been the same or even worse than the deposed government.