While I was making a few tests with the command /entitydata and the NBT Tag "Rotate" for the Armor Stands, I realized that on having executed the command, the Armor Stand was not changing his position. Here there is the command that I have used: /entitydata @e [type=ArmorStand, r=1]

. Not if it is a mistake or a change of Minecraft's 1.8 subversions.