We're forgetting that Sylvanas hates the Lich King to the core and that the thing she values most is her free will. She is undead, but do remember that Forsaken is like the United States of America for the undead. They're free willed and they are no slaves. Why would she imprison herself again to servitude as the new Lich King? She has created a kingdom out of free willed undead. She is a hero among the free willed undead already. She has responsibilities as the Queen of the Forsaken. (The main reason why I made the Knights of the Queen was to shed more light on Sylvanas' character)
I still say Darion is going to be either the Lich King or the Lich King's champion, and we're gonna find out who will be the real lich King before Cata, and not after it (So I'm really not sure about the Thrall thing). The Ebon Knights have no purpose on this earth but to destroy Arthas. They said it themselves. They don't belong to this world. That they are abominations to life. They won't be allowed into any normal society again. With his free will and the fact that he's immortal, I doubt he'd decide to just go suicide. The plausible thing is that he'll take up the mantle of his former master, knowing that he has no other purpose on Azeroth anymore. Knowing that Arthas' former Frozen Kingdom will be their only refuge (Since the living doesn't want them), I'd expect Darion to be like Sylvanas and give the Death Knights refuge in his new Scourge Kingdom. Besides..what do you think Darion will do after the Lich King dies? Be an hero?
'You seem to forget that Darion Mograinne held the exact same position in the Scourge as Arthas Menethil did before he became the Lich King. Arthas was Champion of the Scourge before becoming the Lich King, Darion was Champion of the Scourge before the Lich King's betrayal and his father helping free him from the Lich Kings bonds. In fact you could say that were Arthas failed, Darion succeeded. He may in fact be able to better wield the powers of the Lich King than Arthas could, now that he is no longer a complete slave to the Scourge like Arthas was.' -Some other source of opinion I found intriguing.
In a Blizzard interview around 3.1 when they asked what the future would entail for the Ebon Blade they said, "Someone is going to have to keep the Scourge in check." He weilded the Ashbringer as the Scourge's Champion. Unlike Tirion, their goal is vengeance. A victory for vengeance is hollow; it leave nothing left for him. After getting their vengeance what is the fate of Darion and the Death Knights? Death or 'keep the Scourge in check' the same way Uther described how someone needs to keep the Scourge in check?
And uhh...yeah. Darion was the one who thought up of or was aware of Shadowmourne. Shall he weild it officially? (Officially meaning not you, player adventurer who killed every enemy lore character) He is the only other Death Knight/Dark character able to weild the weapon...other than you, adventurer. And I doubt an adventurer would be the Lich King.
My other bets are Alexandros or Bolvar.
Now as to Alexandros Mograine, Darion's father's role in it, we do not know. He has yet to appear.
Anyway, yeah. Just explaining why I chose Darion with my two cents.
![[Image: Lord_Darion_Mograine.jpg]](http://images2.wikia.nocookie.net/wowwiki/images/b/bc/Lord_Darion_Mograine.jpg)
Your new Lich King?
The Mograine father and son are indeed intriguing.