Warcraft is a beast. You must seriously consider if you're ready to take it on as if you were committing to banned substances. Levels, achievements, heavy multiplayer, many different builds to tinker with, a full economy, gear with no end, and just tons of things to collect for vanity, you really have no hope of having any other entertainment if you start playing WoW.
Yes, this game is extremely fun. If you like anything in gaming you will find something to like in this game, and no one can argue with the strength of the multiplayer, which is essentially 1/4 of the game unless you just love running dungeons and raids. Read more at OCModShop.