Well, I can't do TOO much comparison as I only played WoW in beta and hear lots about it from my friends who play.
EQ2 has better graphics, IMHO. If you like graphics, it is the game for you. Because of this problem, you need a much better computer than for WoW. The graphics engine in EQ2 is designed to scale past the best computers that exist at the moment so that in a year or two it's graphics will still be the best as you can just increase the quality on them.
Gameplay: It certainly favors group play over solo play. My friend who played WoW told me he got to 29th level and didn't actually know where the button to find or join a group was. In EQ2, this is likely impossible or very improbably. As part of the "beginner" section, the Isle of Refuge, the last quest, when you get to level 6 is "find a group and kill an orc". The orc is basically undefeatable if you do not have a group of 3 or 4 at least. The quest is, however, optional.
EQ2 favors more of the D&D flavour of classes combining their strength together to defeat enemies. You pretty much need someone who can take damage, someone to heal, and someone to deal damage. No one class can do all 3 of those things. At least, not well.
It is very quest based, and you get lots and lots of quests. You could spend all of your time from level 1 to 50 without ever just hunting anything. But some of the quests can take a while. You may need to stay online for 8 hours to finish some of them, or finish the quest in parts. All of the best items are either player crafted or given to you by quests.
There is no PvP and no plans for PvP currently. So, if this is what you like doing, you won't like EQ2.
I like it because I love grouping, combining strengths with other people and working together. It's a lot of what I like about D&D as well. Some of us EQ2 players make fun of WoW players because in WoW it's easy to get to the max level within a week or 2 and in EQ2, it would take months, if you powerleveled. Plus, encounters are much harder and less forgiving of mistakes. So, looks for a higher level of challenge as well.