Shoot, now I have to write something.
The aggro system: When you hit a monster with a melee attack, you get aggro. The more damage you do, the more mob hate you gain. Same goes with spell damage. Healing someone who the mob has mob hate with also increases mob hate towards you. The warrior does indeed have a taunt skill that increases mob hate for him.
The warrior and the rogue have their own special fighting systems. The warrior has a rage bar instead of a mana pool. The basic principle is still the same, this is the pool you draw from to use your abilities. However, when a Warrior is at rest, the rage bar is empty. Rage is generated during combat by damage you cause, receive or block and there are also abilities that can raise your rage instantly, should you find yourself low on rage.
Once rage is generated, you can then use this rage to activate your abilities just as you would use mana. After combat, rage will slowly fade to 0 and you'll have to build it back up again to continue using skills. Rage is instantly reset to 0 when switching stances, as well. There are three different stances, each with their own set of moves (which you can browse at Allakhazam's fabulous
Warrior skill list)
Rogues, instead of mana or rage, have energy. All combat related moves take energy. They have opening moves (like
Sinister Strike or
Gouge) which build up combo points. Some moves (like
Garrote or
Cheap Shot) can only be done while stealthed, but have better than usual properties, like large damage or a lengthy stun. Once you have accumulated 1 to 5 combo points (the maximum) you can use a finishing move.
Finishing moves (like
Eviscerate or
Rupture) do scalable damage/buffs/debuffs. The more combo points you have when you use the finishing move, the more powerful or longer lasting it is. All combo points are generic and any opening move can be used to provide combo points for any finisher.
All other classes (exluding hunter, nothing is known about how they work at this time) use mana for their attacks. Yes, their is an auto attack that just has you attack normally with your weapon.
You certainly don't have to do quests to level, and you can gain quite ample experience just wandering around killing monsters, but if you don't do quests you're losing out on giant chunks of experience, money, and items. The game basically revolves around the questing system, but you're never forced to do them. If you wanted you could wander in the wilderness for five minutes, kill some monsters, gain some exp, and log off.
The ability system is most certainly not like Diablo. When you level, you go to a class trainer (located in villages or cities around the world) and pay the trainer money to learn abilities if you are of the appropriate level to learn said abilites. You are not limited on the amount of abilities you can learn. To get Rank 2 of a spell or ability, you must have Rank 1. You'll likely learn all possible abilities at level up anyway, since nearly all of them are quite quite useful.
Priests are probably the easiest class to get a group with, but no classes have trouble finding groups. There is no Shadowknight in WoW ;)
I know I posted what classes are good at what somewhere, but now I can't find it, blechem! I'll just say there's much more of a blending of roles in WoW, it's not cut and dry like EQ.
Being a different race gives you a minor statistical variance. There is no gimped class/race combo. [Edit: Oh, there will also be different racial traits (innate racial bonuses) and perhaps race-specific talents, so there will be a difference, but nothing crippling, and they're not in yet so I can't comment on them at this time.] A warrior with a weapon *will* do more damage over time than a mage with the same weapon.
There we go.. all done.
Edited, Tue Jun 15 15:16:17 2004 by JAEFo