Awww! So Michael Brown decided not to call 2003 UB313 Xena afterall. The official name is Eris, the goddess of Discord. Brown gave the name partly referring to the controversy about how to define a planet that was sparked by its discovery. The small companion object of it is named, instead of Gabrielle, Dysnomia, the daughter of Eris, the goddess of lawlessness.
It is a fitting name, a better one than Xena in my opinion. And it especially makes the little Discordian inside me happy. (Yes, I speak of the religion disguised as a joke disguised as a religion.)