Minecraft wiki entry for Development_versions, associated text: Now follow the same placement rules as lanterns when being placed on the undersides of blocks. As a result they can now be hung from the bottom of the following blocks:
Anvils (all stages)
Brewing stands
Chains
Chests
Ender chests
End rods (facing up or down)
Fences (all types)
Flower pots (including potted objects)
Glass panes (including stained)
Grindstones (ceiling attached)
Hoppers (downward facing)
Iron bars
Mob heads
Pistons (sideways facing extended)
Trapped chests
Walls (all types)