With Storm Peaks done, it was time to move to the other endgame zone: Icecrown. I have only completed a few dozen of the 140+ quests in the zone, and it seems that Blizzard did spare the best for the last.
Icecrown is the first zone where phasing was built-in all the way. The main plotline starts with the Argent Crusade camp, which is being sieged by the Scourge. If you listen to Tirion Fordring's and the Ebon Watcher's dialogue, the Ebon Watcher correctly observes that the Lich King is using Tirion Fordring's morals against him by using captured Argent troops as meatshields. Fordring, being unwilling to kill his own troops, won't use artillery to break the siege. And that's where you come in. After you free the said meatshields (who, being paladins, buff and heal you), you get to the next phase, where the battlefield has been cleared of friendly troops and thus you're free to use the artillery. After you've mopped up the rest of the Scourge, there is an another phase transition and the former battlefield quiets down. Soon afterwards you'll get a quest to start the next offensive to secure the next foothold. When you complete the quest, you gain access to a brand-new quest hub that wasn't on the map before. While seeing a full-size tower appear during the ten seconds it takes to return the quest is a bit funny, it's better than the alternative.
The Ebon Blade also gains a base with phasing. The deathknight on board the Horde airship , the Orgrim's Hammer, gives you a quest to contact an undercover death knight. The agent then instructs you to defeat and recruit a geist, a banshee and an abdomination from the Scourge outpost. Those three then help you fight an elite deathknight within the outpost. When you win, the Ebon Blade takes over the outpost, bringing along blacksmiths, vendors, an innkeeper, a mailbox, a flight master and all other usual amenities. And the three Scourge you recruited before stick around as questgivers.
So far, so good.