343 Industries, the company that's been entrusted with the Halo franchise, has revealed the first full details about Halo 4 and the Halo trilogy at HaloFest.
The first piece of information was that Halo 4 will be the first game in what's now been dubbed as the "Reclaimer Triology". Although no information was revealed about Halo 5 and Halo 6.
Back story for Halo 4 was revealed though. The guys working on the project appreciate that you've seen a lot of architecture and environments of a certain nature in the previous Halo games and with Halo 4, they want to change that. They want to sow a different aspect of engineering and architecture.
343 also revealed that Halo 4 has been in development for a couple of years already and that over 200 employees are on the project. These people have been pulled from 25-30 different studios, so there's plenty of diversity on the team.