My skin has got an overlay which is rendered incorrectly in 15w47a.
This rendering bug also occurs when wearing armor and elytra (also while flying with it). In Inventory, everything's fine. Sometimes the overlay even flickers. Tested in MP. My skin doesn't have any transparent textures (I think...).
Update: Also happens in SP. Curiously, the leggings, boots and helmets are rendered correctly. Only the chestplates and the skin overlay are rendered incorrectly.
For me, It starts to render properly when you hover over an item though when you have nothing in your hand, It goes transparent