The Nostalrius website has word that this "progressive vanilla" private server for World of Warcraft has received formal legal letters they say signal "the de facto end of Nostalrius under its current form." They say they have "no plan for the future," though they do mention they intend to release their source code at some point. There are more details about this in a post on reddit where they say they will host an AMA with the Nostalrius administrators at noon eastern time today. Thanks Kxmode.