Bungie's new game is an MMO, the studio confirmed at GDC 2011 today.
Bungie lead network engineer David Aldrige told a seminar crowd the news whilst discussing netcode in a presentation titled: 'I Shot You First: Networking the Gameplay of Halo: Reach'.
According to IGN, Aldridge referred to the project as a "massively multiplayer action game".
Although other details were thin on the ground, Aldridge debunked a rumour that the title would resemble "WoW in space".
The title is part of an all-new franchise, which Activision plans to exclusively publish as part of a ten-year deal.
The first hint that Bungie's next project would be an MMO came in October last year and the rumour was strengthened in February of this year via a reportedly disgruntled ex-Bungie employee.
Activision holds the belief that the new Bungie project has long-term potential.