Keith Crain has great insight into the car business, but I'm guessing he drives a big vehicle and perhaps doesn't relate to the fact that some people might like the midrange punch of a diesel in a smaller, lighter vehicle.
Frankly, I'd love a diesel in a small SUV such as the Jeep Liberty. Some of those small SUVs really aren't that light (the Liberty included) and manage mileage in the low 20s. So a small/medium-sized SUV that gets 30 mpg would definitely appeal, even with somewhat higher diesel fuel cost.
Does that mean I think that manufacturers should run headlong into the diesel market? Absolutely not, because of the reality of diesel fuel production.
There is a limit to the amount of diesel that can be derived from a barrel of crude oil, and should we see greater demand for diesel than gasoline, the price of diesel would skyrocket (and a glut of gasoline would cause its price to plummet).
So except for a few manufacturers who arrive early and tap a loyal and enthusiastic group who would buy light-diesel vehicles, it is probably best if Europeans drive diesels, and we drive gasoline vehicles.