He's apparently called 'Hiroshi' by the development team informally, which, to an English speaker with a very very poor understanding of Japanese (i.e. me), sounds like a pun on 'hero', and 'shi' meaning 'white' or 'light'; so, basically, his name is 'Light Warrior'. (Please by all means correct me on that though! I'm so sorry for butchering the Japanese language there!). He's also called 'Meteor' (short for 'Meteor Survivor' on the
Waning of the Sixth Sun DVD that came with the Collector's Edition of ARR. And of course, his First counterpart's name is Ardbert, who resembled his ARR/1.0 'End of an Era' appearence physically.
Really though, he's just a stand-in for
your character, and so his 'canon' name is whatever you want to call him (and thus, your character's name). This is appropriate as he is also a reference to the early FF games which also had you playing as a party of generics only identified by their Job classes or their fates as the 'Warriors of Light', it's in keeping with the series' roots.
Incidentally the 'Derplander' nickname came about as a joke on the 1.0 forum about how his early trailer renderings in 1.0 had him pull some very silly faces, and the name kind of stuck (although now he's long since passed that and is now variously and fondly nicknamed either 'Darklander' or 'Daddylander' depending on your preferences.

).