In a future update Valve plans to add two maps to Counter-Strike: Global Offensive by revisiting the classic map Cobble, alongside the creation of an entirely new map called Overpass.
Unlike some of the other Counter-Strike maps, Cobble's large size caused long range firefights and encouraged players to seek out higher ground. The huge distance between bomb sites and choke points leading to each site, shifted any momentum a team gathered. For the re-release of the Cobble, Valve wants to keep the large scale while also making it a viable map for 5v5 team play. Other improvements include to-scale environments to achieve a more realistic architectural structure.
For the second newly designed map, Valve created Overpass – a vertical map comprised of one bomb site in a public park beside an open canal. Overpass offers wide open areas for the Counter Terrorists to throw smoke and flash grenades before infiltrating.
Valve continues to develop each map and should release both in a future Steam update.