Microsoft has released a new set of images for Halo 4 : two new in-game screenshot, showing Cortana and the mysterious Mechs have seen in previous movies, there are a couple of new artwork and render in-game models of various characters. Apart from Master Chief taken from various angles, the most interesting is probably the new appearance of Grunt, now certainly more threatening and with a face that might remind one of a predatory fish. You can find everything here.

Update : added images of a Spartan IV and a sniper rifle DMR (Designated Marksman Rifle).