The game is a bit harder on my computer than WoW is, I even have less of a problem playing EQ II. But it is definitely worth it!
I've been playing for over a week now, reached lvl 17 and crafted my own armour. Crafting is very similar to WoW, to say the least, so it does help if you have played that game.
I'm on the European servers (unfortunately, again no global servers, I always liked playing with people from all over the world, but that's finished I suppose), there are loads of players around.
It's easy to find a fellowship, easy to do quests (relatively speaking, some are very hard, most are fun) and best of all: spawning is very fast. Sure, lots of people might want the same kind of mob, but they usually spawn back very fast so everyone gets their targets fast. I've seen queueing for some targets even.
Graphic wise, I can't say all that much, I need to upgrade my vid card and perhaps double my memory to 2 GB, right now I'm playing at medium I believe, lagging a lot in Bree but it is very playable outside the city.
The game is based on the books, which is good as it has a tremendous amount of areas and people and story not seen in the movie. Just don't expect everything to look like the movie, different copyright.