Gail,
The Chinese are buying up diesel to run stand-by generators because of power shortages.The recent earth-quake has made the very tight electricity availability even worse because of hydro dam damage. SE Asia, and possibly middle east refineries sell of surplus gasoline to Australia, and probably US and rest of world.
Until China can build enough nuclear and coal power plants to supply electricity diesel will remain at a premium. India's new refinery that is designed to use heavy crude may also ease diesel shortage when it comes on line later this year.
If US has to go to rationing, better to be on gasoline as many essential services will get the diesel first. Also increases in CAFE standards should mean more a reduction in gasoline use. Fast tracking real big improvements in CAFE( INCLUDING SUV'S AND LIGHT TRUCKS)could really hold down to some extent further gasoline price rises.

I think you are right about the Chinese and diesel for backup generators. I think we are seeing more of that in other parts of the world.

I agree with you, too that rationing of diesel is likely to leave little for the regular driver.

I don't think CAFE standards are going to be all that important. They phase in too slowly. The economy will be in such poor shape by the time they become effective that there will be few new cars built. People are already sufficiently frighted by the high prices of gasoline that they are looking for higher milage cars, and I expect that to have a fairly big impact now and in the near future. The changed attitudes is likely to do more, quicker, than CAFE ever could.