Spartan Ops Episode 7 begins the push for the climax of the first season of the "Halo 4" episodic series as Dr. Halsey shows why she's the most dangerous woman in the galaxy while on her quest for knowledge. The UNSC Infinity is rocked from another angle as well with an invasion from the Prometheans and Covenant.
Grifball got its start in "Halo 3" as a custom-game goof from an episode of "Red vs Blue" but it now has its very own playlist in "Halo 4" with six maps and two gametypes. For the full details on the maps and settings for Grifball, please read this article.
Lastly, two more Specializations were unlocked and are now accessible for everyone that reaches Service Rank 50 in "Halo 4". You can check out the two new unlocks below. The final two Specializations will be unlocked for everyone next Monday, Feb 4.
Engineer: Spartan optimization for the subversion, repair and reconstitution of a wide range of technology, including Covenant and Forerunner complex networks. The Drop Recon Armor Mod allows users to predict the location and time of an Ordnance Drop through an external suborbital monitoring system.
Stalker: Spartan optimization for target shadowing missions which require tactical invisibility despite operating at an extremely close range to the target itself. The Nemesis armor mod allows users to target and track down previous attacking enemies, highlighting them on the armor’s passive sensors.