From Gamerscore Blog

Beginning Monday, September 3 at 2:00 a.m. PDT, the Hidden Fronts Map Pack will join the Annex gametype and Multiplayer Map Pack 1 as another piece of free downloadable content for “Gears of War.”

That includes the following four maps

Bullet Marsh
In this Kryll-infested swamp, an old generator still powers the area lights. A few stray bullets could easily knock out the generator, leaving combatants to fend for themselves against the Kryll.

Garden
This overgrown and crumbling conservatory still has a working fertilization and pesticide system. This system can pose a serious hazard to anyone who ventures into the greenhouse without first venting the air.

Process
Fight for control of this subterranean Imulsion processing plant, still active despite the cessation of the Pendulum wars.

Subway
Timgad 's Central Subway station used to serve as a central hub for commuters. Now the tunnels are crawling with Locust.


Seeing as I JUST got my Gears back from a friend, I'd be willing to give these maps a go.