The Division: Item Drops and Crafting in Update 1.1 | Latest news and content about Tom Clancy's The Division game
High End items are 100% drop on Named Enemies. Item Levels are directly related to the enemy levels. HE Division Tech drop rate increased.
Named Enemies have specific loot tables, so farming something specific (IE gloves), can be easier if you find a boss that has gloves in his loot table.
Looks like a decent update thanks to this. Farming Challenge mode should then give you guaranteed higher item level gear. And Higher level DZ will be more rewarding!