Since todays patch (4.0.1) i noticed that flying mounts are extremely buggy. Firstly, certain mounts such as netherdrakes and protodrakes do not flap while moving forwards anymore, which i assume will be fixed. Secondly if you are above water and you press 'X' to move down, your flying mount lands on the water surface, then simply dismount and you are left standing on water. This is pretty much useless, however there could be some uses for it, maybe for fishing.