Just to chuck my oar in, I started playing WoW about a month ago, and I won't say there aren't issues. The levelling process is, as many have said, a bit too fast & easy - I feel I've skipped a large part of game content because I outlevelled it, such as most of the vanilla end-game raids and a good half of the Outland BC stuff. The other pain in the arse is the twinks you run across - people who have been playing for years and lay out retarded amounts of gold to gear up alts and dominate battlegrounds, and heirloom items to boot - a constant blue equivalent piece of gear that levels with the character who equips it, making other players about my level far superior even beyond their experience.
Saying all that, I'm still really enjoying it. If I'm not working I'll play maybe half the day, and an hour or two if I'm home from work about 18:30, I've found a guild of people I really enjoy chatting to and help me out if & when I need it, and for all that people whine (and my god, do they whine) about how good the game used to be, I still enjoy it a great deal.
All in all, I'd suggest getting the trial. Avoid PvP servers, they're full of crackholes. I personally play on RP servers because the community itself tends to be more mature, though you're bound to get a well-populated ignore list after a couple of days in any of the big cities, and on Argent Dawn stay the hell away from Goldshire - ERP happens there, and it's dark & perverse because you know it's a bunch of kids letting their imagination take the place of experience. RP servers also seem to be less elitist than non-RP servers, especially PvP. I can't stress enough how PvP servers are full of dicks.