The Alderaani known as Bouris Ulgo "gave us pants" according to Daniel Erickson's joke at the PAX presentation. However, the truth is Ulgo is the self-proclaimed King of Alderaan. What role does the House of Ulgo play in the conflict on this independent planet? That is yet to be discovered, but we do know Ulgo has gone mad since the return of the banished House of Thule (not the one from the EverQuest expansion -- it confused me, too.)
Diab Duin is the Sullustan diplomat Supreme Chancellor entrusted to keep the secret of Aeten II. It is possible the Chancellor believed this quiet pessimist would be over-looked by Imperial spies and assassins, but one this is for certain: the secret of the stygium crystals is safe with him.
When one has risen to the the upper echelons of Imperial Intelligence, he loses his personal identity and becomes known only by his code name. In this case, we are talking about the "Keeper." Every unscrupulous deal of assassination or territorial infiltration is controlled by the Keeper. If he fails at his job, the Empire is quick to replace him.
To find out more about these spies and nobles of the SWTOR universe, check out their biographies on the official site.