Some of the titles sound and look very good and i could see them coming in the future. Like these ones best; Watchman, Cultist, of the Serene Forest, Sunwalker, of the Relentless Soul, Deathstalker, of the Dusk.
Class/race specific titles __if they in no way alter the mechanics of the game__ would constitute balance-neutral flavor enhancement to the game
therefore i am all for class/race specific titles.
Of course it might take a LOT of resources to develop quest line for all the various specific class/race combos, so an efficient method of streamlining the process would need to be instituted (e.g. each class gets a shared quest line, but every race that has acces to that class gets a different accomplishment title upon finishing the quest line)
Why not role it into this new proving grounds they are making? get better than gold? get a title or you went 50 rounds in the endless match up? get a title and the proving grounds is role specific, DPS/TANK/HEALER so you should all ready be in the role you want to get the title on.