I'd be happy if I could at least get a system which drives itself on highways. The majority of time spent in my vehicle on long trips is on the highway anyway - if I could drop the wheel during that time to do something more meaningful, I'd take it in a heartbeat.
I've recently installed a cruise control system on my car, and it was one of the best purchases I've ever done. Worrying about the speed you're driving seems to be a small matter until you try cruise control. Then you realise how much more relaxing driving long distances is.
The one thing I wish is that the cruise control know the distance to the car in front of me, and automatically adjust my speed if the other guy is going slower, to keep a safe distance. This type of technology is already common on expensive cars for automatic braking.
Then I guess the next step would be if it would "see" the lane lines and adjust the steering wheel to always keep me in the centre of the lane. The sensors for this also exist already on expensive cars to warn you when you start drifting outside of the road.
This is the path I always envisioned towards eventual fully autonomous cars, but it seems most projects I've seen are trying to go for the full monty. I wonder if there's a reason for that.