I think paint companies should focus their efforts on paint durability.
I'm sure each and everyone of us that owns a car, would love to see a few less chips, dings and scratches. No matter how hard we try, and no matter how much some may not want to admit it, all of us have a chip, or scratch that we would love to see disappear.
I live in a climate that experiences winter conditions 6 to 7 months of the year. To combat the winter, road crews love to use sand, salt, magnesium chloride and gravel to maintain the roads. These conditions wreak absolute havoc on a cars paint. There isn't a car up here that has escaped the ravages of the road. Wether someone drives a Honda, or a $75,000 SUV, each car and it's owner would love to have a more durable paint.
I'm sure conversely, (as vat_man has mentioned before) that a cars paint, especially blacks and reds, are torn apart by the sun in the warmer climates.
My car for example, (although Lexus is notorious for it's soft paint) has areas of it where all the paint has been chipped off. My car is black, and there are large white spots, about the size of a fist, near the rear wheels where rocks come up from the road and mercilessly rip the paint off the car.
If I could turn back time, I would have had my whole car covered in that 3M clear bra material. And I mean the whole damn thing.
I would definately trade some of a paints shine and luster for some added durability.