There was a good amount of information given to us yesterday in the bulletin. I’m going to go over what i found important.
NOTE: POSSIBLE SPOILERS!!!
Campaign Info
-Gravity Hammer
Gravity Hammer is confirmed in the game, however brutes are confirmed out. There are story reasons for the hammer being in this game, as stated by Frankie.
-Hunters!
The classic halo enemy is back as they are associated with two campaign achievements.
-Skulls
Skulls are back! although there is no achievement for finding them, so they may be returning the way they did in reach 
-Terminals
Terminals are back! achievements associated with locating them.
-Chiefs record
there is an achievement for finding this on the first mission. are there multiple records throughout the campaign? no one knows…
-Missions
there are only 8 missions. the length of these missions are currently unknown, but 343 employees have stated on twitter that the # of missions doesnt effect the length of the campaign. it is still standard halo length. I am still dissappointed though, but hopefully these missions will be nice and lengthy.
Here is what BS angel said about the number of missions
> The number of levels in the game (as revealed via Achievement listings) has no particular bearing on the length of the Campaign – and our levels are split thematically and for reasons of fiction as much as they are by location or “map.” There are a couple of instances in the game where a “level” actually comprises different environments and radically different play styles that might otherwise have been split into different levels. In terms of length of Campaign, it’s similar to most other Halo games and the number of hours to complete will depend on difficulty level, number of players and play style, just like before. Some folks will rock as many vehicles as they can and try to blast through as fast as they can, while others will stare at every rock, blade of grass or hidden corner and take weeks to get through a level.
>
> And Halo 4 - in a doubling down of the grand tradition of previous Halo games, encourages exploration, experimentation and replay with all sorts of methods, from hidden story content, to achievements, to easter eggs and beyond.
>
> Over and above that, every copy of Halo 4 includes access to Spartan Ops, with ten weeks of content, and five missions for each of those weeks means that in terms of story-driven gameplay experience, this has far more single player and cooperative content than any other Halo game, period.
Here are the Missions and what i believe goes on in each (many still unknown)
Dawn-First level on the FUD. We’ve already heard of this mission, and i cant see it being any longer than 30 mins long
Requiem-when you crash on the shield world. Involves a warthog! Could also involve much exploration and a real time system, as there is an achievement revolving around making a big jump at MIDNIGHT.
Forerunner-Unknown, could be when the chief discovers the cryptum?
Infinity - Judging by the name of the mission, i expect this to be the mission shown at E3. This mission also involves marines (according to one of the achievements) meaning that we may do more than just reach the ship. This will probably have the cutscene shown at SDCC.
Reclaimer-This must be the mission in the desert that we’ve seen in trailers as well as screenshots. It invloves at least 5 wraiths according to the achievements, and the desert mission definetly looks like it involves vehicles (one screen has 2 scorpions in it). The return of BIG VEHICLE BATTLES!!!
Shutdown-unknown
Composer-unknown
Midnight-unknown
Spartan Ops
-Marines!
Marines are confirmed in spartan ops!
-RVB easter eggs!
Confirmed in spartan OPs!
MP, Theatre, Player cards, and Ranks
-SR ranking system
this may be the new skill based ranking system. SR5 and SR25 are two ranks seen.
-Theatre mode
confirmed in!
-Player Cards
You can now change your pose!
-Challenges
theyre back!
PAX 2012
-Reborn Trailer
Will be developer commentated, will discuss campaign characters, gameplay, weapons and vehicles.
-New gamemode!
a new game mode will be revealed alongside a new map!
