There are way too many characters that have been ignored by Blizzard.
Of course they can't fit all of them in each expansion, but some have been ignored for too long.
A favourite of mine being Khadgar. He should be in charge of the Kirin'Tor, not Rhonin or Jaina.
Nazgrel, Thrall's right hand man has been sitting in Outland for too long.
Jorin Deadeye, son of Kilrogg.