It's estimated fuel economy will improve in the range of 0.6 to 1 mpg. Less fuel will be used because electric assist only consumes power when turning, compared with hydraulic power steering in which the engine has to drive the pump all the time.
Parking assist is also an interesting development which will enable cars to parallel themselves (Toyota offers such a system in the Lexus LS460 in North America). These are further steps that are necessary to reach full electrification, when cars will be ultimately powered by electricity.
The last reason seems of dubious value to me as reported. It doesn't seem that road crowning is much of an issue. However, the real benefit of electric steering may be that it can lead to independent steering of left and right side wheels which would allow for self-diagnosis and alignment of the front axle. Manufacturing for left and right-hand drive might be simplified as well.
Further, it is possible that when electronic stability systems kick in during an emergency, the rotation of the steering wheel won't need to be directly proportional to what is actually happening at the tires. This could reduce risk of injury to the driver's hands (especially thumbs) due to steering wheel whip, when he or she loses control of the vehicle.
All in all, it seems a logical direction on the path toward driverless cars.