Well, look at your server pop. Dragonscale is geared towards 60-mail wearers, whereas Elemental and Tribal are both useful to rogues and droods alike. By far, I would say there are a helluva lot more rogues and droods than hunters and shamans, so I would have to say Elem or Tribal have the most potential. However, knowing how to exploit said potential can make anything profitable.
Sorry for the not-straight answer, but seriously, you can make alot of money of any of them if you sell the right stuff at the right time to the right crowd.