So i completed the Illidan storyline on live now, though i had to put myself through this rather painful questchain, the finale just blew me away.
Not the Illidan fight, no, the completion questtext for a character that killed Illidan. (The questtext is different for DH and character that did not kill Illidan)
http://www.wowhead.com/quest=44481/destiny-unfulfilled
Personally, i couldn't stand Xe'ra and this Illidan praise, yet the final sentence just takes the cake.
So the story Legion concerning Illidan is not about him, but rather we have to redeem ourselves because we killed him.
So Illidan moves from a grey character, to a pure villain, to the ultimate good in the Universe that we foolishly killed while our hearts and minds were corrupted by hatred.
I don't have any issues with the player character not being the ultimate hero all the time, but this is just awful.
Edit:
If you did not kill Illidan:
If you're a DH.