What has WoW done that's right? What have they done that other MMORG developers and live teams need to take note of?
Singularly, they have removed the "gotcha, hahahaha!" from the MMORG experience. Prior games, particularly Everquest (but also notably Galaxies and Dark Ages of Camelot), had a us vs. them mentality. The Us was the hapless players trying to have fun, while the Them was the developers looking to trap players with frustrating gameplay and impossible quests.
In Everquest, a "quest" is very difficult to find. It's difficult to figure out what you should be doing and where you should be going and looking to do it in. You always have to look offline to an external quest site to figure things out. And then, once you've finally pried the information you need for the quest out of the ether, you then are facing the prospect of actually completing it.
In Everquest, "quests" are like playing the lottery. Whether they're to kill a certain mob(s) or collect a certain item(s), you had to deal with the Developers' idea of likely occurance. Basically, on a server, X number of instances of the needed mob or item would appear over Y time. Problem being, X and Y were both far too big. You would "work" on a quest for days, weeks, months or even years sometimes. To get quests done "quicker" you had to camp and grind away until the random number generator rolled your lucky number and gave you the Magical Enchanted Widget of Quest Completion.
This basically sucked. Classic reward psychology shows behavior is encouraged by rewards. Prior MMORGs have a very low reward vs work payoff; you spend dozens and dozens of game hours to complete one goal. Often, by the time you finished the quest, you were sick of it, didn't need or want the reward anymore, and were definitely ready to be done with that area you'd been stuck in.
WoW, however, takes a delightfully refreshing approach to gameplay and questing. Quests are an integral part of WoW, which is quite amusing considering "everquest" is supposed to have this sort of game play, but SOOOOOOOOO doesn't.
In WoW, quests are everywhere. You can easily identify quests; whether you are eligible for them or not. NPCs are clearly marked that they have a quest available; you don't even have to talk to each person in town to see which have quests. Simply walking up and looking around will show you which NPCs are offering quests.
Further, the quests are designed to be (gasp) FUN! The quests are very clearly worded with both color text (the stories and in game reasons for this quest) and instructions. The quests don't offer impossibly cryptic puzzles and riddles like EQ and DAOC do, but rather say things like "southwest of Riverville, past the mountains, there are nests of monsters. Kill 5 of them and bring their toes to Gyllian Herbmixer in Riverville so he can make magical potions."
There is a screen that shows you all the quests you have right now. You can instantly check on the exact progress of your quests anytime you like. Each quest ticks off your progress, 5 of 12 items collected, 3 of 7 monsters killed, etc... Further, as you collect or kill, you get a visual update on your HUD that's unmissable (5/12 appears right across the center of the screen for a few seconds).
You can even view the quest reward before accepting; it'll show you what you're questing for, be it money or items. You can abandon a quest at any moment you like and the quest will reset back to the NPC for you to start again later if you like.
Basically, the quests are fun. They structure and enhance the gameplay. They do all the things a proper MMORG quest should do; provide a guide for your online play, encourage you to explore areas and investigate the local flora, equip and pay you with items and cash you need at that time, and reward you with experience that is an important part of your character leveling experience.
WoW is a home run that's still going, long story short. Everything about this game is user friendly and designed to be fun. The virtual environments are very real feeling and extremely enjoyable. Cities and villages have the distinct feel of a real place due to the appearance, and due to the other players cycling through to talk to NPCs and engage in commerce. Cities in EQ and DAoC always seemed empty and unfinished; not so here.
If you're playing another MMORG, you owe it to yourself to find a friend who's playing WoW and look over his shoulder for a little while. Then beg him to get up and let you play for an hour or two.