Quote from Pizarro
As for the zombie with arrows in its back.
It sounds like a new feature to see injured mobs. As for assuming the zombies and skeletons working for each other now, thats wrong. Notice how the zombie is looking dead on at the skeleton, its obvious the arrows in its back were from the skeleton.
It also looks as though arrows are actually sticking into the mob, maybe arrows will stay on the player too. ...*Wonders if there's a way to remove them*....