I don't know if this is for feral as much as any arena team out there. Last night my 5v5 team downloaded an add-on called Proximo. This is awesome. All you have to do is mouse over the other team and it adds their information to a box on your screen. Tells name, life, and whether hunter, shaman, etc...
You can also click on the bar with that info to target them, no more running around arena looking for them. And since you can see how much life they have you know where to focus. All I know is this add-on made things sooo much easier for us, I'm feral and I loved it, but I think it would be useful for any arena team.