Dave Spohn over at about.com has wrote an article outlining the similarites and differences between Everquest 2 and World of warcraft.

Apart from the fact that the graphics in both games are excellent, there is a big difference in the artistic styles. World of Warcraft looks a bit like a comic book or an animated movie. Polygons have been kept to a minimum, but the environment has a tremendous amount of detail. Water and light effects are acceptable, although nothing dazzling. Nevertheless, it's one of the most attractive MMORPGs yet, and a trip on a Wind Rider does not disappoint.

The most common complaint seems to be that there are, at the moment, a shortage of integrated ways to customize the GUI.
EverQuest II has a much more "realistic" appearance, insofar as a fantasy game can be said to look realistic. Familiar things like humans and bears are quite accurately proportioned, with relatively smooth edges. The scenery is gorgeous, and even the facial expressions are impressive. Sony has employed DX9 to create water, lighting, and spell effects that rival those of the latest first-person shooters. EQ2 does have the higher system requirements of the two games, which may in itself make the decision easy, and you will undoubtedly need to exceed those requirements to run at the highest settings. (See the end of this article for the system requirements of the two games.)

Check out the whole article here.