The third episode has been released for Halo 4: Forward Unto Dawn.
Halo 4: Spartan Ops - Episode 7 Trailer
The seventh episode of Halo 4: Spartan Ops is shaping up to be an action packed one, according to this trailer.
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.
Making Halo 4 - Part 1 and 2
Join 343 Industries on a 20 minute behind the scenes featurette on the creation of Halo 4.