I've been on the hunt for a while after leaving wow a few years back, tried a bunch out (dozens really). Bought, beta'd, or just bugged friends to tell me about them to figure out if I should bother doing either of the former.
Here's a
List of a few.
One of the things that you'll find is most "new" MMO's aren't as polished as WOW is, only older games have had the time for that level of development. Respect to it, for that. Which means you're trading some of that polish off for something else. It might be a new and engaging combat system, genre, storyline; and the promise that perhaps a ways down the track it will develop into something more robust. The former is a matter of opinion but that last point can be weighed somewhat by gauging the developers past performances. Even if they're built by different studio's you'll tend to find the handling of the project isn't that different, which speaks to the level of refinement at launch, postlaunch support, and further development.
Hope you find what you're after.