After too much deference to plaintiffs' lawyers, reporters lately have begun giving a more balanced treatment to this story, as “black box” information begins to reveal that some cases most likely arose out of the driver's pedal confusion.
While researching Inviting Disaster, I interviewed Bob Young of the NHTSA about sudden acceleration cases and he said that upon close investigation the majority of cases showed no mechanical malfunction and were likely due to the driver putting his or her right foot on the gas pedal while thinking it was the brake pedal. Then they froze up as a horrifying set of crashes followed; panicking so thoroughly that they didn't take even a simple action like turning the ignition off. One point that Young made struck me in particular: if while sitting on the street, somehow a car's throttle really had moved itself into the full-power position and then had stuck there (unlikely but perhaps not impossible in a drive-by-wire electronic system), the driver's foot if pushing fully down on the brake pedal at the same time (as drivers claim they did) would have overpowered the car's tendency to lurch forward. That's because the brakes in a street-legal car have more ability to decelerate a car than an engine has to accelerate it.
I do agree that drive by wire systems have many more failure modes than mechanical linkages so getting to the bottom of this is a priority.
Pointer: if SAI happens to you (and it's more likely after age 55), turn off the ignition as you hit the brakes. It's the fastest and surest way to stop the car.