Healer dispels are big here, with freedom for dk/pally and sac to break healers out of cc they have plenty of pressure during cds with 2 5 second ranged stuns post priest fearbomb. And if you survive the cds, thats where rets crazy offhealing and dks crazy solo pressure still keep you on your heels while not being able to do a whole lot to land kills. Dunno, the times ive played against it seemed pretty strong, and with spriests/hunters/rogues being nerfed and rets being buffed it can only get stronger.