I'll say it again since it's clearing going whooosh.
FEAR IS NOT BREAKING ON DAMAGE A CERTAIN PERCENTAGE OF TIME. THERE'S NO REASON FOR THIS. IT HAS BEEN HAPPENING SINCE THE BEGINNING OF THE EXPANSION. IT IS STILL HAPPENING NOW. AND IT IS STILL HAPPENING IN 5.3 PTR.
Fear, for all intents and purposes, is a stun currently. Except spammable and lasting twice as long as most stuns.
---------- Post added 2013-05-05 at 01:47 AM ----------
But that still does not mean fear is weaker. Fear is BY FAR the strongest CC in the game bar none. It is effectively a polymorph that does not heal your target, does not break on damage and effectively peels your target off you. This is compounded further by the fact that there are many MANY more ways to fear your target than there is to CC your target in any other way.
Despite the amount of fear breaks in the game I would argue there aren't nearly enough.