At a PAX East panel, 343 Industries announced that Halo 4 is getting a "Forge Island" map. The name itself is a nod to the "Forge World" in Reach. The map will be available on April 11 for free, letting Forgers tinker with a series of large open spaces.
Kotaku also reports that a few other updates are on the way for Halo 4. A skill ranking system will be introduced that's more similar to the one found in Halo 2 and Halo 3, by assigning skill numbers from 1-50. A new title update will add markers to show where teammates ahve died, make players using camo more visible when they shoot, and adjusting the Gauss Warthog turret's auto-aim, magnetism, and damage.
Steve Watts posted a new article, Halo 4 'Forge Island' coming on April 11.
The Halo 4 panel at PAX East revealed a few upcoming additions: a free Forge Island map, a new skill ranking system, and a title update with balance adjustments.