Earlier today, Bungie announced on their website that they were forming a partnership with Activision. They will remain independent but they will be able to reach a much larger audience. The partnership spans ten years and gives Activision the rights to publish and distribute future games developed by Bungie on multiple platforms and devices.
Their first focus is to release Halo: Reach, a game they're claiming is the "most ambitious" one they've ever made. After that, Bungie promises to keep making "kick ass games that we want to play."