Okay so after seeing that Onyxia's model has been re-skinned along with Nefarion's I'm curious to see where she will appear in the first batch of raids.
All signs pretty much point to Blackwing Descent... but the achievement:
Objectives
Blackwing Descent
Defeat the bosses in Blackwing Descent. Magmaw
Dark Iron Golem Council
Maloriak
Atramedes
Chimaron
Nefarian
Clearly does not show her... Does this mean the list of raid bosses is not finalized, 'as in the bosses could be switched around?' Will she only appear in a hard mode with Nefarion? I have searched around a bit and haven't found any answers. Feel free to enlighten with any information you my have about this issue.