Perhaps he does, perhaps not -- regardless, for all purposes, Nathanos Blightcaller is dead. In Cataclysm he is nowhere to be seen and the Marris Stead lies deserted, save for a few of his beloved blighthounds that still patrol the property. Nathanos himself? He is referred to as the "former occupant" in a quest, but that's all we hear of him. The story of Nathanos was always somewhat special to me -- the first character I ever made dinged 60 upon completing the quest to kill the Blightcaller, and the second dinged 60 turning in a quest to him. I'd always hoped for some expansion on just who he was, where he'd come from and how exactly he got in with the high elves in the first place, but it looks as though that story will remain untold for now.
As for the Forsaken, although Nathanos would have been an excellent, logical choice to train the new legion of Forsaken hunters were he still alive (and undead), they aren't without a teacher. Sylvanas Windrunner was, after all, the Ranger General of Silvermoon -- and after she regained her body she became the first dark ranger. According to the RPG books, dark rangers aren't quite like the hunters and rangers we know in WoW -- rangers themselves are highly attuned with nature, and death severs that connection, so the dark rangers turn to shadow magic rather than the natural magic of the wild in order to accomplish what they used to do.
Hunters in Warcraft work a little differently, and I'm sure the undead hunters will use the exact same spells as their other racial counterparts, but it wasn't until Wrath that we began to see more and more of these dark rangers running about. The dark rangers of WoW are undead high elves, doubtless former members of the Ranger General's corps that were turned into banshees themselves, and regained control of their former bodies in the same way that Sylvanas did. Several of the dark rangers that players encounter share names with random dark ranger heroes from Warcraft III, so these characters have been around for quite some time -- they just didn't have a presence in World of Warcraft until this point.
So we have a few working theories about the forsaken hunters -- Nathanos may have trained a few individuals during his time as Champion of the Banshee Queen, or perhaps the dark rangers have started taking non-elven undead under their wings. There's also a third, much more grim possibility, and it lies with another organization that has roots in the former kingdom of Lordaeron -- the Scarlet Crusade.
The Scarlet Crusade was originally created to combat the scourge menace, but things quickly turned south when the leader of the organization was killed and his body repossessed by the demon Balnazzar. Balnazzar was one of three dreadlords that watched over Lordaeron and the scourge in the name of the Burning Legion back in Warcraft III. When Archimonde fell during the Third War, Arthas returned to Lordaeron and informed Balnazzar along with his two brothers, Detheroc and Varimathras, that he would be taking over the city and the Scourge, and promptly kicked the dreadlords out. Needless to say, this did not go over well.
The three dreadlords worked with Sylvanas and helped her regain her body and attempt her revenge on Arthas -- but what they did not expect was that Sylvanas would then turn on them. She persuaded Varimathras to join her side, had him kill Detheroc as a show of his allegiance, and then attacked Balnazzar's base, where Varimathras "killed" Balnazzar when he would not join sides with the Forsaken. Balnazzar escaped, but he swore his vengeance. When the Scarlet Crusade invaded Stratholme, he possessed their leader in order to enact that vengeance.
It didn't take much to push the overly zealous members of the Silver Hand to form the Scarlet Crusade -- an organization devoted to wiping out the undead. And it took even less pushing to cause the organization, formed under what was though to be a noble cause, into performing unspeakable acts in the name of "justice." The Scarlet Crusade turned from an organization devoted to destroying the undead, to an organization that killed anyone and anything on sight -- after all, if a lone human were wandering the forests of the Plaguelands, it could be and should be assumed he was in actuality an undead, just freshly raised.
The Scarlet Crusade fought viciously against the Forsaken, as well as any other force that tried to stop them -- obviously, if someone was trying to prevent them from carrying out their righteous duties, they were invariably allied with the undead that the Crusade sought to eradicate. Among the members of the Scarlet Crusade were a notable number of human hunters, including Houndmaster Loksey and Huntsman Leopold.
Over the course of World of Warcraft, the Scarlet Crusade has been finding themselves slowly losing their war, and by the time Cataclysm comes into play, the Scarlet Crusade is a shell of its former self. Few members remain, and those that do remain are quickly dying out. The Forsaken may have taken this opportunity to raise several of these dead former Scarlet Crusade hunters and used them to train hunters of their own. A grim fate for those once fervently seeking to eliminate all undead -- to become the very thing you spent your life trying to destroy. But as we've seen from many of the spoilers surrounding Cataclysm -- it's a grim expansion.
As for the human race, and their sudden interest in the hunter class -- one thing to keep in mind with the humans of Stormwind is that they've had a fairly shaky history as of late. The kingdom of Stormwind was utterly destroyed, and then rebuilt -- it could very well be that there simply was greater need of other tasks than hunting. Or, given the dissolution of the Scarlet Crusade, it could be that some former members have left the ranks and joined the Alliance whole-hearted, and agreed to teach others in the ways of the hunter as a sort of penance for the atrocities they committed while serving the Scarlet Crusade.
At this time, it's still largely unclear why the hunters chose Cataclysm as the time and place to show their faces -- but with the way the Forsaken is being portrayed, it seems as though they need all the help they can get. As for the human race, perhaps the years of fighting side by side with their night elven and dwarven allies are finally rubbing off, or perhaps the crumbled remains of the Scarlet Crusade are now meekly offering a hand.
Regardless, the hunter class is relatively easy for roleplayers and storytellers to justify if needed -- the class choice isn't quite as far of a stretch as previously thought, unlike other race and class combinations that have left people mystified. Combinations like the noble tauren, and their sudden interest in paladins and priests. Next week, we'll take a look at the "holy cows" and how they fit, along with a dive into tauren history -- or what exists of it.