Sydney Hostage Standoff Ends With Three Dead

A standoff with a gunman who held customers and employees of a cafe hostage for more than 16 hours finally ended earlier today. Two hostages and the gunman, a self-described Muslim cleric named Man Haron Monis, are dead. Several others are injured. What happened, what do we know about the perpetrator, and what could the political ramifications of the incident be in Australia?