The eighth CG episode is out for Halo 4: Spartan Ops.
Axis Animation Behind the Scenes of Halo 4: Spartan Ops
Axis Animation go behind the scenes on their amazing Halo 4: Spartan Ops CG cinematics.
Halo 4 Trailer VFX Breakdowns by Method Studios
Method Studios do VFX breakdowns of several scenes from their recent cinematic trailer for Halo 4.
Halo 4 - Concept Art Trailer
There is some inspiring scenery in this concept art trailer for Halo 4 from 343 Industries.