most enjoyable game i've ever played. it can really be as complex as you want it to be. a lot of people spend a ton of time and energy discussing different spec builds and the math that goes along with making their char's the best. check out the forums on the wow website to see what i mean.
war'crack' is very addictive. maybe that's because there really isn't an 'end' to it and you just want to keep getting better and better.
plus the replayability is awesome. level one guy to 60 (soon to 70) and then try a new race/class/faction/profession and have a whole new experience.
you also have pretty good pvp in the BG's and in the game world (on pvp servers).
i'd recommend it...and you do get a 30 day trial...and i could probably get you a 10 day trial account if you could borrow the disks from a friend and install it.