Actually, Kil'Jaeden comes before Arthas in The Sunwell Plateau.
And Ner'Zhul was not "just and orc" he was one of the most, if not the most powerful orc ever alive.

about some of these people:

Ragnos:(or how ever you spell it)is NOT a titan,he was the fire elemental gerneral for the old gods when they was very hostile towards to the titans that wanted to make this new simple world that had no life execpt these "gods" Ragnos and 4 other generals was slain tho they was ELEMENTALS.the Old Gods there was 5 of them that had 5 citidals,but was defeated by the titans but was so powerful they could not be killed so they are in 5 differnt vaults DEEP within azeroth.and just one of them cant be killed by 10 titans(there is 10 titans i think total)and they can summon an elemental army by them selves.so think if one of them is bad think about all 5 so those twilight people are idiots thinking that they will be spared.

Sargeras:IS NOT A TITAN,he was their BEST TROOP,he got really depressed about killing alot of the nethrezem(deadlords)and the edar.so thus he made the burning legion and made Archimond the Corrupter and Kil'jaden the Deciver his generals and Archimond liked the pit lords and had the strongest and best of them Magtheragon the Destroyer his gneral and Kil'jaden liked the dreadlords so he made the most powerful one Tichonderus the most cunning and powerful his little general type deal.but he hated the titans by now and wanted to destroy all of their work and he came to azeroth for the Well of Eternity,but azeroth had to sacrifice it to kill him,so thats where the malestrom came from,Azeroth was once one content now is 3.

Illidan:Killing him is a BAD thing,if you played WC3 remember when he shut down those other portals...well those are the once Ner'zul opened to escaped Kil'jaden.and now he wants to shut off the last one "The Dark Portal" to make Outland cut off from the other planets to keep the burning leogion from ever going to azeroth.BUT right now hes keeping all of those others closed(AKA no burning legion reinforcements)KILLING HIM=Kil'jaden can bring the rest of the burning leogion to outland and where the "Dark Portal"is not closed...guess what?say hello to the other leader of this big legion oh and Archimond only brought the army of outland there....there is Hundreds of planets tooken over by the burning leogion.and they are pissed so guess what?we have 8 planets declareing war on us.so blame the naaru for when we are all dieing.and also...Illidan saved the blood elves from dieing...and Keal'thas sent his army to shattra city to enable illidan to shut off the last portal.but thats the Scryers now,and also...the blood elves in azeroth are waiting for Keal'thas to come back home,so killing Keal'thas will piss them off.and i dont want to talk about all of the warcraft lore to him.But he did make the 2 well of eternity giving the night elves imortality...thats why he was imprisioned.in my opinion...id be greatful that i can now live forever...but hey...they are elves -_-

Archimond:Why the hell did they make Illidan stronger then him?HE WAS MORE POWERFUL THEN KIL'JADEN just more stupid.and he took out daralan with one spell and illidan shits himself at kil'jaden...so why is illidan stronger then archimond if kil'jaden makes illidan piss himself?and they ned to make him ALOT bigger....if you beat WC3 rain of chaos(not frozen throne)Archimond was almost as big as the world tree.and note:when he dies a BIG exploesion happens.but they had to TRICK archimond....or we would not be able to play this game because we would all be D-E-A-D.im not going into his lore.

Manneroth:all i got to say is hes the strongest pitlord to ever live and he made all the others piss their little for legged ass to hell.

Ner'zul(Litch King):He taught Gul'dan as a Shaman while Kil'jaden Taught Gul'dan as a warlock.Ner'zul was basicly a Thrall in his day,but he pissed off Kil'jaden and needed to flee...so he made some portals but he needed some items to make them work...and we had them in daralan.thus starting the 2 war,when he got them he came back to outland and the army of the allience came through with him to finish off the orcs whn ner'zul opened the portals the energy was so powerful it was tearing the planet apart and both the humans and orcs fought their way to azeroth and only 2 clans made it,the Warsong clan was being led by Grom Hellscream if you play WC3 you will know him.and the Frostwolf Clan,the Frost wolf clan was put into slavery and thats where thrall comes into play,but back to ner'zul....Kil'jaden found him as he was traveling to another world.and tore his body apart but kelp his spirt attached to it so he would feel the pain,and ner'zul begged to die but Kil'jaden kelp him alive....then he made him a deal,he would give him eternal life and a new body if we weakend azeroth for the main attack by the legion...so he accepted.when he got there he was in a ice shard and the ice around him shifted into a throne.but he soon was finding out his powers was becoming limitless (his mid powers that is) and he was directly putting the plague into the villigers of the land,and he now could move hunterds of troops doing differnt things with ease.then the nerubians and him got into a war...he could not but the plague directly in them but when they died...they would serve him.in the end he won.but now he has taken over that land.and now he sent out a physcic wave and thats where Kel'thlazad comes in....he left daralan to find the litch king....and he finally went to northrend....when he got to the litch kings citadel we was confronted by skeletons....but they did not kill him...insted he was able to meet the litch king...he willingly offered the litch king his soul for power,the litch king liked that so he took it happly,but let him keep control of his body and his humanity.and kel'thlazad came back and hid for 4 yeas making a cult of the damned....but the litch king also knew that kil'jaden would kill him when he was no longer useful...so he searched for a champion....one that didnt know the differnce between the light and the dark.and he found Arthas Menthil.

Medivh:He was the most powerful magic user that had mortal blood.he was part high elven and part human,his father was a powerful mage that was addicted to magic,his monther was the gaurdian of tirisfal.both his father and his mother put their powers within Medivh before he was born....he didnt have the powers until he was 13 and went kinda crazed with it.and he made contact with the most strongest orc to ever live...Gul'dan.He now has been talking for him for some time....and medivh wanted to know so much about outland...that he offerd Gul'dan to read his mind while he read Gul'dans....gul'dan let this happend...but the info he coundent get,it was moving so fast and there was so much that gul'dan was getting nothing....while medivh.....found out a great deal of info....but the Gul'dan broke the connection and hid for 3 weeks in the Neather storm....until Medivh found him again....then thats when medivh made the deal about telling Gul'dan of the tomb of sargeras...if he brought in the orcs to azeroth to rid medivh of his enemys...so they accpeted.and gul'dan worked on one side of the portal while medivh work on his side where the portal was now functional.thats when the orcs took out stormwind.and did much and medivh kelpt his end of the deal.and medivh died sending out ALOT of phycic energy that made gul'dan unable to fight same with alot of the Shadow Councile when the warcheif invated their keep.and later Gul'dan betrayed the warcheif and took 1/2 of his troops to the tomb....leaving the orcs unable to destroy lorderean.


(sorry for the bad grammar and pretty much this stuff you can find if you read the books and play the games so try and prove me wrong and tell me wich page you read it and the book...or tell me wich mission....)
(sorry for some miss spelling,im not going to go into everyones lore.)

Well if you ask me the next thing we'l be dealing with >after< we get to kill the lich king (a.k.a. Arthas formed up with ner'zhul's spirit armor) is the thing i've been hearing about through the WHOLE game.. called "the nightmare" or something.. wich is growing up in the emerald dream, first i hear that Malfurion has gone into a never ending sleep of the emerald dream, wich cause is "the nightmare".

later on you'l kill eranikus where you'l find out that he got corrupted by "the nightmare". after that when you reach about level 60, you'l get to see the >"nightmare"< dragons who also got corrupted while guarding the gateway to the emerald dream.

after you kill one of them you get the quest that explains the whole thing by malfurion himself that he's fighting vs "the nightmare" INSIDE the emerald dream..

Wich comes to the conclusion that the next area we'l all get to
move to is the emerald dream, cause i see some links between it all if you ask me.

i've also found some quotes on wowwiki that might be of any interest:

Rumors dating back to the early development phase of World of Warcraft in 2003 suggest that the Emerald Dream may be added in a future patch or expansion pack as an endgame zone or as a new continent. New speculation suggests that the Emerald Dream was originally intended to be an endgame instance, but got scrapped because Blizzard wants it to become the main theme of an expansion. Tigole stated in late May 2007 that Blizzard has "actually done a lot of work on the Emerald Dream but we scrapped what we had for bigger, grander plans."

>Blizzard quotes<

As for the Emerald Dream, there are no plans for anything as of yet but it is a consideration for the future. The Emerald Dream opens up a lot of different opportunities and the Burning Crusade is definitely not going to be the last of the expansion packs. There are many different places and storylines that can be pursued. The story is going to keep growing and as it does so, people will get to experience it.

just my thoughts of one of the expansion packs coming up...

Well, you sorda got a point, but at the same time, you don't. Ragnaros was weakened a bit, and C'thun was EXTREMELY weakened. Ragnaros pretty much just came back, and C'thun nearly (or maybe he did and he just escaped) got trapped underneath Azeroth. You got a point with Sargeras and Nefarian though.

Lol dude ur wrong, the lich king was a humane

Considering this was out six months ago i really am talking to myself and this whole responde page is a hostland, but recently in the new patch you do get to kill kiljaedan. he doesnt fully die though, he just gets bitch-ass raped and loses all his mojo, before going baq to the sunwell were he acme from. Arthas is fightable to in the next expansion.