A great game, but DO NOT PLAY IT
I'll keep this short to get the message across.
-WoW is highly addictive, and offers a very wide variety of gameplay options to satisfy nearly anyone.
-The different classes and races are very well fleshed out, as opposed to the standard Warrior/Thief/Mage base most RPGs use
-The story, if you could call it that, leaves much to be desired, but that doesnt at all mean that you wont feel like the hero of azeroth at times.
-PvP is very fun, whether you're a competitive player in rated arena matches or someone who just wants to have fun messing around in a battleground, but balance issues between the classes will always hamper your experience (see Death Knight)
-Raids are immersive and immense, provided you can find a large group of other people. If not, dungeons offer a quick respite
-For many, the game actually "starts" when you hit max level, since below-level-cap PvP is limited and raiding is non-existent (not including dungeons). Therefore, you can consider time spent up to that point (which will be a LOT) pretty much wasted
-Professions are implimented very well, though oftentimes they wont be useful until you reach the maximum level. The in-game economy is robust
In conclusion, the game is very good, but for the love of god DO NOT PLAY IT. The stories are true, people do get sucked into it, and more often than you might think. I recently escaped after a failed earlier attempt to quit a few months back, and though I came out ok, I know people who have had their lives LITERALLY ruined. LITERALLY RUINED. There will always be something to draw you back in, whether its a new raid instance, changes to the class mechanics, or simply the feeling that if you left, all of your work on your character will be wasted.
DO NOT PLAY THIS GAME. You will have a good time, but you will regret it...oh will you regret it...