In the new five mans (Forge of Souls, Pit of Saron and Halls of Reflection) Jaina Proudmoore is the Alliance NPC with a score to settle with Arthas, and she does a fine job and all, but Sylvanas... none of this conflicted, he was once my boyfriend, how can I kill the man I once loved stuff with Sylvanas. No, Sylvanas is all about one thing, and that one thing is killing Arthas: she only retreats when she's taken over five million damage! That's pretty stubborn.
In general I really enjoy the lore moments in both versions of the new five man, enough that I'll keep trying to run them as many times as is possible just to get to see them. Not to mention the climactic moment of the Deathbringer Saurfang encounter (which I completely spoiled for my Alliance guild... sorry, guys!) and I'd love to see the (heavy spoilers ahead please don't watch if you don't want to be spoiled I warned you this link is spoilertastic) Horde equivalent, perhaps on 10 man sometime soon.
So, how are you liking the lore of Fall of the Lich King so far? Not enough, too much, just right? How is your lore porridge, baby bear? Sorry, I haven't gotten to sleep much, too much PuGging.
Patch 3.3 is the last major patch of Wrath of the Lich King. With the new Icecrown Citadel 5-man dungeons and 10/25-man raid arriving soon, patch 3.3 will deal the final blow to Arthas. WoW.com's Guide to Patch 3.3 will keep you updated with all the latest patch news.