Xenoronin is an Interface MVP on the EU forums, most known for his Pimp My UI that he releases every week. He's not the original author of PMUI, Schwick is, however Xenoronin took it over.
Some small facts about Xenoronin.
Source on this is himself, on the #wowui channel @ QuakeNet IRC.
"[23:01] <@MVPXenoronin> i'm 18, male, and from ireland"