WoW encapsulates everything that is both good and bad about MMORPG's: There is always more to do, but alot of it is repetitive, time consuming, or both. Much of the high end stuff requires a good group of fellow players to properly be enjoyed. If you just jump in yourself, it will be much harder.
Speaking of players, The community is vibrant, however, these days you will be on your own through the lower levels on your way up to the current content. This will make some quests exceedingly frustrating and difficult. I'd seriously recommend a leveling guide, it will make you life less frustrating and the journey that much faster.
If you didn't enjoy the solo aspects of the early levels, its likely you won't enjoy them ever, depending on class, solo is the most fun in the early to mid levels. Hunters are good pretty much from start and pretty much the whole way through, Mages, meanwhile, take until their twenties to get fun (the first twenty levels aren't per se challenging, you just don't have enough abilities to fully play with the class yet), and then become challening again around the 50's, if going solo.
It is absolutely possible the game will suck you in, but that's something you have to gauge in a personal level.
Your big questions should be, basicilly:
Do I get annoyed at depending on other people for advancement/progress?
Does grinding, be it for money, materials, drops, or whatever, bore you?
Some people love the communal aspect (maybe the find a good guild) and some people love the "lottery" of finding good drops, other people find the whole thing to be a soul killing experience.
