In the nigh on three years that I have been playing World of Warcraft I don’t think I have loved a quest chain this much, ever. I know I haven’t thought anything was this awesome since I did the initial Death Knight starting area chain.
Starting w/ a great Cinematic of Alliance and Horde fighting side by side (Thrall!) against the Prince of Darkness (no, not Ozzy), and then having everyone being pwn’d by Putriss and the Forsaken, in a hard core way, this was by far one of the most fun things I have ever done, next to that failed attempt at For the Alliance (it was not well led, at all*). As an Alliance toon it is the only opportunity you have to go to Ogrimarr and not get the shit beat out of you (if you are smart you can run and do a rare fishing quest while you are at it).
It ends w/ you accompanying King Varian Wrynn (who is frickin beef) and Lady Jaina Proudmore on a raid to take the Undercity back from The Forsaken. You get a mad buff (similar to the one in the DK chain) that makes you nigh un-pwn-able, and the three of you storm the Sewers making your way to the Apothecarium.
At the end you run into Thrall again (apparently he didn’t die on the battlefield)…and Varian turns into a bit of a tool box. If you know some of the backstory surrounding Lady Jaina and Thrall you won’t be surprised at how it ends (though, I found it slightly anti-climactic, to be honest).
If you have been hesitating re-activation of that WoW account or upgrading to Wrath of the Lich King you should totally do it to experience this chain. So much fun.
Almost makes me want to dust off one of my Horde characters to try the chain from the other side.