A friend sent me a link to this.
Ink is a self-described PAW, or "persistant alternate world." It's designed to teach writing and foster a community. Similar to MUD or MOOS, Ink says they are different because "Whereas other games invite players to swing swords and slay dragons, Ink challenges players to communicate, cooperate, compete, and achieve through writing."
It looks very interesting, and I will likely visit them when they 'open' on July 1.