From Blizzard's New MMO Wiki
Bungie is the company behind the Myth adventure games along with the most successful First Person Shooter game - Halo.
On 2010, Bungie and Activision Blizzard agreed on a 10-year worldwide partnership. The partnership refers to the creation of a brand new IP of an action game universe by Bungie while Activision Blizzard will have the exclusive rights on its publishing on multiple platforms and devices. 
On February 17, 2011, Kotaku reported a rumor of Bungie's new game being called Destiny.