I most heartily concur. The lead up to Yoggy was engaging, all the quests in Storm Peaks merging and answering questions, while introducing new lines of inquiry. The raid at the end of quest chains blends perfectly with the quests, both answering, and bringing up more questions. This was Blizzard at their best imho. TOC was just numbing. No point to it at all except enough gear to assault ICC. No connection to the Icecrown quests that lead nowhere and are not engaging on their own. The expac hit a high point in Storm Peaks and has been coasting rudderless ever since. Yes I want to kill the Lich King but the story from COS to Icecrown spurted and lurched, a book outside the game provided more info than the quest chains. I found it unsatisfying.

Ideally the activities of the Scourge should have gotten MUCH MUCH stronger and wild with the elimination of Yogg-Saron, as the entirety of the God of Death's powers flowed into Icecrown Citadel.

The Icecrown zone should have become much more dangerous, with giant elites being mixed in with the marching undead. Malykriss could have launched prematurely and appeared over settlements Kalimdor and EK settlements, re-enacting the Scourge invasion. We could have had the Scourge show up in Wintergrasp.

ToC could have been a consolidated HQ for the post-Yogg-Saron world, wherein all Undead hit just a bit harder, and specfic Undead hit a LOT harder. The Sunreavers and Silver Cov could have organized tactical responses to hit the Invasion hotzones, and offered daily quests to eliminate the Event bosses in the various old world Dungeons.

It is good that we are thinking about Arthas. It is awesome that everyone is totally obsessed by Arthas. The races of Azeroth, their attention centered on that little citadel to the north and the master of the Scourge who rules it.

That leaves the rest of the world quiet and undisturbed so the Old Gods can continue quietly working away at their real task - having a chat with an old friend who's currently taking a siesta in the Elemental Plane.

(This is merely my tinfoil hat speculation, mind you.)