In Destiny's new The Taken King expansion, Xur will have an impressive new buff that will significantly boost exotic item drop rates--but you'll have to gamble to get it.
During IGN's PAX 2015 panel, Bungie dev Luke Smith revealed that Destiny's interstellar merchant, Xur, will have a new buff that will make it rain exotics: "What Xur has on him is an item that lets you basically gamble the chance to find an exotic on the next enemy you kill."
"Xur's still going to show up every week, he's still going to sell some amount of exotics," Luke Smith iterated when asked how the infamous Agent of the Nine might change in the new expansion. "But now he's got a new mechanic that we're not talking too much about yet, but it's a new way for you to sort of gamble and get exotics out in the world. We're pretty excited about this."