Autonomous long-distance HGVs will indeed be the first commercial application of this technology. The fuel saving alone from 'platooning" along motorways, let alone the reduction in down-time because autonomous vehicles don't need to park up for a snooze, make the economic case very compelling.
I suspect that Uber-style pseudo-taxi services will be the first significant growth area in car-sized autonomy. To be able to summon a car from a mobile app, go to wherever you need to be, and dismiss the car without having to worry about finding (and paying for) a parking place will be, again, compelling for economic and convenience reasons, particularly in urban and suburban environments.
All the statistical analysis points to autonomous cars being much, much less likely to be involved in an at-fault collision than human-driven vehicles. The industry with the most to lose from autonomous vehicles is not any of the car manufacturers, it's the insurance business. The scuttlebutt in North America, at least, is that the big insurers are bringing huge political pressure to bear to delay the widespread adoption of autonomous vehicles, driven by the commercial reality that they will lose a major revenue stream as premiums inevitably tumble.
Edit to add: Journalist Chunka Mui has written some insightful commentary on this topic for Forbes magazine.
http://www.forbes.com/sites/chunkamui/#5580c0336a35