Is Iran on the Brink?

What began as demonstrations due to a falling currency has now turned into calls for the end of the regime. After 3 weeks, protests have now spread across Iran as the regime gears up to celebrate its 47th anniversary. With its regional proxies in retreat and Iranians on the streets demanding regime change this has now become the biggest test of the clerical regime. Is this the beginning of the end? Can the masses finally overthrow the regime and what will replace it?