I would love the AP re-write to incorporate a probabilistic path prediction into the UI. Cut-in detection seems to be relatively simple ("What do the few frames of video look like before a car cuts in?"), it's a binary "is cutting in" or "is not cutting in" prediction (that probably has a non-binary activation threshold, but that's not exactly what I mean when I say probabilistic).
Imagine training a 4D Autopilot rewrite on all of the human driving behavior observed by the cameras to date. Instead of predicting binary states, you could predict co-dependent future positions based on speed, signals, angles, etc (90% chance of maintaining speed and lane, 5% chance of accelerating, 5% chance of merging to the left, etc.). It's something I do subconsciously as a human driver ("Okay, this guy is in an exit lane to my right, but he's accelerating, what are the odds that he's going to leave the exit lane at the last minute and cut me off?") It would be very useful for human drivers to see a graphic representation of where the system thinks each vehicle around it is headed (with little shadow vehicles of varying opacity, or vector-like arrows of varying direction and length).