I have lots of fond memories of WoW. I really enjoyed the leveling and the exploring of the different zones. The art direction is top notch, although the game is showing its age. Where the game got boring for me whas when I hit a personal glass ceiling of available free time / gear I could obtain with that time. As already stated, as with a game that focusses on character progression or developement through leveling or gear you come to a stage of diminishing returns. IMHO the best part of the game was the leveling and I can't attest to how populated the lower stages / dungeons are at this point.
I would say give it a shot if you have nothing better to do.
I would say give it a shot if you have nothing better to do.