Don't any of guys really know, there is going to be a Halo 4 (or more likely a new trilogy), which has been announced by Microsoft in 2006. The Game is going to be made by Peter Jackson. (As it says in the wikipedia article on
https://en.wikipedia.org/wiki/Untitled_Halo_Project).
"The Untitled Halo Project, codenamed Chronicles, is an episodic project first announced at Microsoft's Xbox show, X06 [1]. Peter Jackson and his recently-formed Wingnut Interactive will create a project set in the Halo universe, in partnership with Bungie Studios. The game is toted to be a "new chapter" in the Halo story and is slated to feature a new way of playing games. It was later revealed that it would in fact be a new trilogy of games, not a single release. [citation needed]
The British Xbox 360 magazine Xbox World 360 speculated that the game will be more of an "interactive movie"; some parts will be semi-playable, and certain decisions will lead to different outcomes [2]. They also speculated that the game could retail for half the cost of a normal Xbox 360 title.
At the 2007 Game Developers Conference Shane confirmed that the project will be episodic. According to Microsoft, Bungie and Jackson are planning two episodic series for the Xbox 360. These games appear to be in a downloadable format. Microsoft stated that the game is now in the development phase."