WIth the addition of the custom loot tables for mobs, the Enderman doesn't drop the item they hold anymore. The Enderman was holding a grass block but when he died, he drop an enderpearl but NOT a grass block when he should.

Zombies also doesn't seem to drop the item they had in there hand even if it's an item thrown at them. After killing about 300+ zombies, no rare drops occured, not one ingot/armor/sword/carrot/potato, just rotton flesh.