Pretty funny-- Mania's Arcania issued a challenge to Alliance Hunters a few days ago to do something that might be impossible: tame the Shadowmoon Village stablemaster's pet wolf, Detrafila. The wolf is level 60, and according to Beast Lore, is actually tameable. But he's also surrounded by level 70 Horde, of course, so taming is not easy. Plus, some "pets" of NPCs are actually summoned pets, and therefore not tameable.
But two Hunters were able to pull it off. Dezar on Black Dragonflight and Gettokiwi on Stormreaver were both able to kite the stablemaster away from Shadowmoon Village, take him out, and then tame the wolf after he'd dropped. Unfortunately, as far as I can tell, the wolf doesn't have a special, identifiable look, and he doesn't actually come with any abilities, so there's not much reason to do it except for the experience.
But it would be exceedingly cool for Blizzard to "hide" special tameable pets like this for expert Hunters to go after. I know there are a few other "special" tames around-- Spot in Menethil Harbor is one, as is Stanley, the dog the Horde poisons in Hillsbrad. But it would be cool to see a few more secret, more select tames for Hunters in Northrend. What d'ya say, Blizz?