They've been working on this for a few years, now.
It's basically an engine that encompasses the entire Earth (and some) as a sandbox game map but is still very much in the alpha stage of production (and may never see the light of day).
There is a proposed game for this engine called Anteworld. If the game is ever finished, It will throw the players into the world where they can, build, mine, form cities, states, countries, currency, armies, start wars, form space programs, launch satellites. Players will be able to control a person as well, not just drive vehicles around.
Source unclear...
An undertaking of this size will surely take years and years to complete so I won't be holding my breath, but if it does ever come to fruition it will surely be teh awesomes!"Anteworld is a world-building game on a massive true-to-life scale of our planet. Returning aboard an interstellar colonizer ship built in the Golden Age of Mankind, players arrive on the planet earth to discover civilization and humanity vanished. They will have to rebuild the civilization - exploring, fighting, and competing for resources while searching for clues to the disappearance of humanity.
The game will contain several modes, the basic one will be a single-player game but with player-built locations being synchronized and replicated between clients. That means player can settle in a free location of his choice where he can build and play, and when he goes exploring he'll be able to observe and visit other sites where other players are building their world."
http://en.wikipedia.org/wiki/Outerra
