I don't think the algorithms would be easier with two cameras than with one -- geometry detection is pretty straightforward and well-known. It's being done in the MobilEye chip, so any efficiency difference or preference would probably be based on MobilEye's implementation. My guess is that while two cameras may not be a cost issue for Tesla, it was a factor for MobilEye in designing their system to be as affordable or have as small a footprint or power requirements as possible for its intended purpose at the time it was designed. A disadvantage to a one-camera system though is that the car needs to be moving to get a true stereoscopic effect (it may be able to do some clever deduction if other objects in the scene are moving, but whether that's possible and how well it'd work is beyond my knowledge). This is probably fine for highway autopilot but would likely be limiting in other situations where there's a need for something like pedestrian placement, particularly when stopped at a light. It's hard for me to say exactly what the new cameras will and won't help, especially without knowing whether they are accompanied by a new chipset (isn't the current MobilEye chip limited to two camera inputs?).
