check out: http://topservers.beer-garden.org/nexuiz.php
As of this post, eatseakittens.com is the second most popular Nexuiz server in the world. Some of the most active Nexuiz players (in the world) are the “regulars” on eatseakittens.com. Only about 1550 people are actively playing Nexuiz. Seems a little low, but not shocking.