As some of you suggests Demon Hunter, Necromancer, Runemaster, Monk and Blademaster, etc as the new hero class to come.
You all forget a the most important thing around presenting a new hero class, and that is -how it will be presented- as we see with Death Knight, they are build around the arch enemy Lich King, servant of him, risen by him but break free.
If you want to discuss, suggest what could be the next hero class, start there.
#1 What could be the next expansion theme?
#2 What could be the next arch enemy in the next expansion?
#3 Then how is the hero class involved, connected with the theme or arch enemy of the expansion?
Also I like to add, I'm 100% for any hero class there must be a master, trainer with significance lore about him.
Who will guide you the first steps? If not Lich King. Who will it be?
A villian?
A friend of both Horde and Alliance? Neutral? Who?