What happens to the world of Azeroth after Arthas falls? What do you think happens to people, factions, etc. What do my characters think happen next? How do I feel?
What I think?
I always hated Arthas. From the moment I played him in the human campaign I hated the character. He was lawful stupid and extremely whiny (and I personally think he's a Stu right up there with Varian and Garrosh), I actually cheated playing through the Undead campaign of Warcraft III because I didn't want to deal with him anymore. I got to the Horde campaign of Warcraft III and had to stop in fear of having the horde ruined to me.
I'm looking forward to kicking Arthas' ass. It'll be great. Finally we'll be able to move onto other storylines instead of the one centered around a whiny emoprince.
What my characters think, however, is something completely different. I do play on a RP server and I have put some thought into my characters and their feelings.
My Paladin, my main character, is mild-mannered. He does what he does, the guild I run only pseudo-exists ICly, they're not terribly strictly IC, though some of us RP sometimes. The paladin would likely view it as all in a day's work. There'd be little reveling, simply moving on to the next issue at hand. He's more concerned with the care and protecting of those under his watch. The fall of Arthas is not nearly as important to the paladin as, say, the Sunwell related storyline was, where it was implied that the Blood Knights were the turkey all along, and that their 'stealing' of the light was wanted / intended.
My Deathknights were written as a pair of priests, brothers, members of the Argent Dawn who died in the original Naxx back when it was in the Plaguelands. They will probably find themselves feeling a bit more outgoing, no longer having the weight of the past on their shoulders, getting closure by knowing the force that brought them back and corrupted them. They'll probably go on pretending to be priests on a righteous path, but using their Deathknight skills to do good instead of evil.
Most of my other characters are pretty indifferent with the exception of one, my hunter.
My hunter being a raiding character actually has a good chance of actually seeing Arthas fall in one of our alt runs. He's a character who, for the most part, does not speak at all. I've been playing the silent act with him since late April of 2008 when I created him. He was leveled without having him ever speak outloud ICly or OOCly. I spoke outloud on him in a raid once due to fail (but raids are ooc so it doesn't count) and in three situations where I felt it necessary for him to speak... proving that he can but chooses not to.
One of those occasions the little hunter has spoken was driven by my own OOC ire. When someone said "Oh? He doesn't talk? I'll just read his mind." Having someone read his mind would have really cheapened the whole character being silent. I've spent twenty months without speaking on this character, I wasn't about to cooperate with someone demanding I tell them what's going on in my characters head, especially not a Death Knight. I could see a priest, but not a DK. I don't consent to this random player I don't even know casually forcing a major change to my character as if it were nothing. (WOW Rpers could benefit from adopting Furcadia's Consent Rule.)
The hunter witnessed first hand the razing of Silvermoon as a young elfthing hiding in a tree. He saw the terrible massacre, the carnage, and it broke him inside. He spends some of his time as a mentally regressed coward, he goes between being afraid of undead and something snapping inside of him, causing him to rise up to kick them in the face. It's like Jekyll and Hyde. Cowering hunter hidden badass. So my hunter looked this DK right in the face and very softly spoke words akin to, "If you get in my head I'm going to rip your throat out."
By facing off against Arthas, and seeing him defeated, my hunter shall have faced the source of his greatest fears, the leader of the things that ruined him and shattered him. For just a few moments, he'll go from being a coward trying to fix himself to a pinnacle of badass bravery.
I foresee that in the aftermath he'll heal some from his old mental wounds, that his Jekyll and Hyde sides may merge to form a single being, that he'll go from being a coward to being normal. Most importantly, the silent character may finally speak in moments other than a handful of dark critical ones where something absolutely must be said. The hunter might just come out of his shell.