It definitely removes stun from rogue/knight - strike of punishment, stun from knight - charge.
Doesn't work against blasting cyclone or savage whirlwind from warrior/warden. Not sure about shout, but I think not working against that too.
Removes shadow prison and all roots like lighting, movement restriction.
Wasn't testing it if you use it before stun, but I guess you won't get stunned from most of the skills.
And it doesn't remove Holy Chains from knight/scout.