Frank O'Connor and the folks at 343 Industries showcased Halo 4 at a recent community event in London last week. The embargo for the event has since been lifted, and details about the features they presented have come spilling out at a torrent today.
The map remake of Halo 3's Valhalla map, titled Ragnarok, was showcased at the event in the War Games competitive multiplayer mode. Despite being renamed, the map is a direct remake and not a reimagining of the classic map. That said, the map does see a number of new changes to it including the upgrade of each base—red and blue—located at either end of the map. The structures also feature a Forerunner aesthetic this time around.
343 Industries appears to have taken the game's Armor Abilities into consideration and tweaked the structures to cater to the verticality offered by the Jet Pack ability.
In addition to these additions, Ragnarok also sees the implementation of a new vehicle known as the Mantis. The Mantis is a gigantic mech equipped with a machine gun and a rocket launcher. It walks as fast as a non-boosting ghost with a slow turn time. The weapons its armed with are powerful, but have a heat build-up that you'll have to watch out for as they take awhile to cool down. Like other vehicles in Halo 4, it is possible to be hijacked by another player, so it's a good idea to travel with some support. Highly durable, the Mantis can take a heavy beating before it goes down.
Halo 4 is set for a release on November 6, 2012. It's exclusive to the Xbox 360.