Gerdes, I is a reference to Ian Gerdes who is a Level Designer at Blizzard.
He also appears in World of Warcraft and is in the credits for Mist of Pandaria.
He is rumored to be working on there next Blizzard project code name Titan.
I have tried finding some information on the quote, but so fare no luck more than one place.
Adams, D is a reference to David (Dave) Adams Lead Level Designer on Diablo 3.
He also worked on StarCraft: Ghost, World of Warcraft The Burning Crusade and Wrath of the Lich King and there is a character named after him(some think it is a reference to Grizzly Adams, but he looks more like David Adams).
I could not find any information on his quote either.