For starters, some of the Guild Wars 2 names include some magic from Annie VanderMeer Mitsoda. Today on the ArenaNet blog, she explains the naming process behind most of the names in Guild Wars 2, be it based on real-world lore, established game naming schemes, onomatopoeia, outside media, references to Colin Johanson, or button mashing. Due to the setting and nature of Guild Wars 2, some names are skipped because they either do not fit in the universe of Tyria, or they are not easy to pronounce while doing voice over work. Before a name is finally done, it gets a last pass by Jeff Grubb and/or Ree Soesbee.
Of course with a blogpost, also goes an example, which she gives by stating what name in Guild Wars 2 is her favorite, and how it got created!
Source: ArenaNet Blog