I think Blizzard needs to cut the retcon crap and actually make a race playable that already has some backstory! The Draenei, the Worgen, the Goblins, the Pandaren: what do they bring to the table?
The Draenei were a complete and total retcon. They have an improvised backstory that increased the lore for the Orcs, but that's it. Their main enemy is the Burning Legion, and that's the only time that their lore will ever come through: when we fight the Burning Legion. As for now, they are few in number, and their lore can't grow whatsoever! Even with WoD, we're just going to another timeline and witnessing an alternate ending to the story we already know. Yet, this alternate ending won't appear on our own Azeroth, so what good will it do for us as a whole (and no, I'm not hating on WoD)?
The Worgen can't go anywhere. The curse has been handled and maintained and controlled by them based on the events with the Night elves in their starting zone. It's impossible to find a cure, as well, unless we just want british humans and no Worgen whatsoever as a playable race.
The Goblins we play as come from a retconned cartel that we've never heard of before. To follow, Gallywix tried to kill our playable characters multiple times as well as Thrall, but he's still their leader even though he's no where to be found in-game. That's it. Otherwise, they're just the engineers rivaling the Gnomish engineers.
The Pandaren . . . Yeah. They aren't a retconned race, but their story sure is (or at least it was improvised). I'm sure they will never get any more lore, unless they're trying to resolve conflicts through peaceful tactics. That being said, it pretty much just showed the illogical side of having Pandas put themselves under Garrosh's reign.
So overall, Blizzard just needs to stick with the races that have a developed backstory. The Blood elves are managing fine through lore-progression. Even the High elves, an unplayable race, gets more lore than the Dwarves, Gnomes, and the newer races. Just saying.