Borderlands Online will be coming to China, published by Shanda Games and developed by Gearbox. There are no apparent plans to bring the game to the US.
Four classes will be available in Borderlands Online: Warrior, Ranger, Wizard, and Berserker. The game is planned for a release in 2015; a mobile title is also in development, although it's unclear whether it will be a tie-in to the online game or a port of an existing title. So, yes, that crazy rumor was apparently right on the money.