The tech experts on Ars Technica are compiling a series of reports on autonomous cars, called "The Future of Driving." The three-part series talks about the DARPA Grand Challenge and the technologies it has generated, the potential for integration of autonomous cars into industry and society, and the many challenges that researches and developers still face in really getting this technology going.
There's still a lot of work to be done before these vehicles will be mature enough to be let loose on our streets. Real streets contain significantly more obstacles and complexities than the simplified environment found in the 2007 contest, and the most successful vehicles in the Urban Challenge were not designed to cope with pedestrians, bicyclists, traffic lights, or icy roads. And even when the technology is ready for prime time, a variety of economic and political obstacles could delay widespread adoption of self-driving automotive technologies.
Nonetheless, the success of the Challenge series has made it clear that it is only a question of "when," not "if," self-driving automotive technologies will make their way into car showrooms and onto our streets. It's impossible to know exactly when such will arrive, but it's a good bet that a college student entering the workforce today will have a car that can drive him to work before he retires.