The planet formerly nicknamed "Xena" has officially been renamed Eris, which was suggested by it's discoverer Michael Brown. Eris is the Greek goddess of strife, which is what it's discovery has caused. The commotion ultimately led to the demotion of the smaller Pluto to the status of dwarf planet. Eris has one known satellite and that is now named Dysnomia formerly nicknamed "Gabrielle."
Pluto has always been an interesting object for many reasons and many people are upset that it is no longer considered a planet. However I agree with the new designation, it's orbit was too wild, it is too small and the alternative of adding the other newly discovered Kupier belt objects to the list of official planets is not really an acceptable outcome. Pluto has received it's minor planet number of 134340.
Here is the official IAU designation.