The big opportunity of robocars isn't the cars themselves; it's how they could create a far more efficient transportation system.
When I've thought about driverless cars, which if you believe Sergey Brin, will be available within "several years," I've tended to think of them as a drop-in replacement for our current automobiles. So, you'd buy a VW Automaton and it would sit in your driveway until you wanted to go somewhere. Then, you'd hop in, say, "Take me to Lake Merritt," and then just sit back and pop in the latest Animal Collective while the computer drove.
But maybe that's not what would happen at all. Changes in transportation technology have tended to be accompanied by changes to transportation systems, too. Long-time technologist Brad Templeton argues that this will, in fact, be the case. And he's even got an idea of what the big shift might be. We could enter the age of the "whistlecar." If one can hire a cheap specialized 'robotaxi' (or whistlecar) on demand when one has a special automotive need," Templeton writes, "car users can elect to purchase a vehicle only for their most common needs, rather than trying to meet almost all of them -- or to not purchase at all."
This vision is kind of stunning: imagine the Kiva Systems logistics robots that now speed around major warehouses, but for people. Transportation-as-a-service models could really take off in a world of hyperoptimized robotaxis. Not only would the robotaxis be built differently from normal cars, but people's private vehicles (if they had one) would change as they realized how they could use the new system more effectively.