Haha, that would be awesome, I agree. Unfortunately I think they've confirmed they won't expound on that yet, because in order for the loss to really be a poignant story event, they can't just go, "Oh just kidding, she's back in the next expansion!" I think they will (and should) let it "sink in" for at least this expansion, and then bring her back into the spotlight in a later expansion/game.
Damn right!
After the Invasion of the High Heavens, they pretty much forgot about Leah.
She's never coming back.
She was just another plot device, like typical females from fantasy stories.