Ubisoft Massive, formerly known as Massive Entertainment and developer of the Far Cry 3 multiplayer, has subtly revealed their next project. Two pieces of evidence, a job listing on their website and a LinkdeIn profile for a current employee, both confirm that the studio is working on an a "AAA Online RPG." Further details include that the game is third person and that the project is starting in October 2013, though whether it's a next-gen game or not is unclear.
The LinkedIn profile for Marc Cartwright lists the project as an online AAA RPG for next-gen systems, but he is also the one who mentions the project starts in October 2013. This proves a bit conflicting, seeing as it's doubtful that the next generation of consoles almost certainly won't be released before holiday (November) 2013 at the earliest. That said, whatever the project is it sounds big, like something that's been worked on for quite some time now.
There is an alternative, however, as all that Ubisoft Massive has done since they began working as an Ubisoft Studio is build multiplayer sides of single player titles (see Far Cry 3, Assassin's Creed: Revelations). The details above could very well just by resume speak for the next Assassin Creed's multiplayer. A listing for an audio engineer lists 250 employees at Massive working on several different projects, which makes it difficult to imagine them solely in control of a new IP. Hopefully we'll hear more before October 2013.