Currently in the beta the pandaren passive "Bouncy" says "You take half falling damage."
It does just that, because falling damage is capped at your total hp, if you have 250k health and fall from the sky you will take 250k falling damage.
With bouncy you will only take 125k. So if you have 130k hp and fall from the sky, you will have 5k hp remaining.
Tl;dr you cant really die with the bouncy passive unless you are trying to on purpose