People in general don't, which is sad; I don't want oaths implemented in any binding game-mechanical way, that's for sure. Though it's no use to complain about it if I'm doing nothing; I should work on getting some oath swearing done in Corsanctum when I have the time, but I've been working on personal RP lately instead.
OT: Jonsu & Enoch just made the most infamous list.
Other than them, I can only think of a handful.
Bowie Ironsides
Allison Kabrinksi
Haruka Vanimedle (there was another character in this family that started an earlier rebellion in Niselur when I started playing but I don't remember the name)
Baal Beldragos
And did anyone mention Garret Artemesia yet?
Add Mendicant to the list!