Xonotic 1.0 was talked about at FOSDEM 2012 this weekend in Belgium within the open-source game developers' meeting room. Nexuiz was forked as Xonotic by the community in early 2010 following and their first development preview came more than two years ago. Xonotic did a new release a few months ago, but now this DarkPlaces-based game is working towards the stable 1.0 release.
Merlijn Hofstra was the Xonotic game developer talking in Brussels this weekend. In his presentation he shared that Xonotic v0.6 is nearly here,
Xonotic 0.6 is considered fully stable while bringing lots of new features and being their last step before the 1.0 release. There's now a stats-tracking system, a new menu system, "Sandbox" support for freely moving/editing objects, and tons of in-game enhancements. One of the other improvements over Nexuiz is that Xonotic has support for fully-interactive vehicles, but some of that is still considered a work-in-progress and there's a need for new, larger maps to fully take advantage of the vehicle transportation.
More details on the Xonotic 1.0 presentation can be gathered from checking out the slides, which are available from this HTTP file directory. That directory also hosts some slides and recordings of the other open-source gaming talks from FOSDEM 2012.