I play both games, I also play EQ1. EQ1 was my first MMO, I started playing about a year and a half ago, loved it and was hooked until EQ2 came out.
WoW is fun, but I don't think the world is fleshed out very well, there isn't a lot of incentive to explore, and things stay pretty much the same from beginning to end. As time goes on and I play both games, I like EQ2 more than WoW by a wider and wider margin. Sometimes I just can't bring myself to start up WoW.
First off, EQ2 is definitely not EQ1 - the tactics and class balancing are completely different. Combat is also much more predictable, and the con system leaves no room for uncertainty. Actual combat is very similar to WoW. Easy and repetitive.
If you like grouping EQ2 has a huge advantage over IMHO solo-oriented WoW. All things equal, you'll exp faster in a group than you will solo. Which is not to say you can't solo - any class can do so and make real progress. (I've made 80% of my exp solo.)
If you like game lore, one of the best things about EQ2 is discovering how and why Norrath has changed and seeing the places you know from EQ. I read someone (maybe here) who said EQ2 is one big mystery - and that's spot on. I also feel the world in general is more interesting visually. There's more variety. I mean, aside from major cities, is EVERY zone in WoW a forest with impossibly huge trees or a desert, and do people really only build 3 or 4 different structures? Every zone in EQ2 is different.
Tradeskills in EQ2 are much deeper and more productive financially than in either EQ1 or WoW, by far.
If you're not a min-maxer and you like lore and exploration you'll like EQ2. If you like to grind experience by camping and pulling and hate quests, you won't like it.