By Blood Knights I mean classes which are functionally identical (let's pretend SoB didn't happen) but have radically different lore. So Blood Knights are Blood Elf paladins. The rest of this will contain some speculation or outdated information about Cataclysm, I apologize if I make any mistakes and would appreciate any corrections. I won't delete your comments pointing out my mistakes.
Gnome hunters would play pretty much the same, but use mechanicals instead of beasts and have a much different story to them.
The upcoming Tauren paladins, as I understand the lore, are not paladins in the same vein as Uther, but are instead Druids of the Sun. Again, same mechanics, different lore.
Dwarf mages also have different lore, most likely being castaways from the Dark Iron clan. Dwarf shamans would be similar, but from the Wildhammer. Until now we've only seen Bronzebeard clan dwarves, so this is a pretty significant shift.
Similarly, it appears that Night Elf mages are returning Highborn.
There may be others which I've forgotten. I like this trend of expanding class options without simply saying "you now have X class" and rejectonh all the lore which goes against them having said class. Instead the new class options expand the story and add to the world.