Levelling up in WoW is at a good pace; faster than most MMORPGs, but still slow enough to keep you busy. I have no complaints or suggestions for the quest system. The profession system is pretty good as well: you can choose two major professions from a selection including mining, skinning, blacksmithing, leatherworking, and more. It's a good way to both make money and gear for yourself.
To me, PvP (Player vs. Player) is where the game shines. You're either on the Alliance or the Horde and spend much of your time battling the other faction. As you reach higher levels, you'll cross paths with them more often and you can ignroe them, combat them, ambush them, or get ambushed. It's very frustrating to get ganked during a quest, but it is a war after all. You can organize raid parties of large amounts of people and slaughter enemies in either contested or enemy territories. However, even better is the fact that Blizzard plans to implement Battlegrounds, which, in short, places your character on a Warcraft battlefield, complete with mounted battles, gryphon raids, etc. The future looks promising.
