* Taxi drivers: Probably not going to lose their jobs. Someone has to monitor the vehicle after all.
* Limo drivers: Ditto. Plus the driver is part of the service.
* Couriers: Probably not going to lose their jobs. They're using the car as a tool to get from A to B, the car isn't the thing doing the job.
* Mitt Romney's chauffeur: Maybe, but I doubt that many people have that type of job, and in any case, there's a good chance the job would be kept as the same guy is also responsible for maintaining the car.
* NASCAR drivers: Nobody cares about machines going in circles. It's not worth watching if there's no person in the center of that giant exploding crash thing.
So the answer to the question "What new^H^H^Hcareers do you foresee that current professional drivers would qualify for" would be "The ones they currently have." Professional drivers have their jobs not because they're superbly skilled drivers, but because just about all jobs requiring a car move from A to B require that a person be directly involved.
But before we go on, let's get some perspective:
In London, there are two major rail based transport systems. The London Underground is a huge, traditional, interconnected underground railway which has one person, the driver, on every train. Some trains have more, but the minimum for operation is that one driver.
And then there's the Dockland's Light Railway. Now, that's a modern system put in during the 1980s, and when they created that, someone said "Wait a moment! This is an electric train running on tracks, and we have these things called "Computers" now that can control everything, in theory this train thingie doesn't need a driver!" And so that's what they made, a completely automated train. It's great. The trains don't have drivers. Just, uh, guards, who collect tickets, and make sure passengers are safe and aren't caught in doors or anything.
Computers have a habit of changing people's jobs, not obsoleting them.