As we saw in the early 1980's, many people in the US made sizable adjustments--they traded in large American cars for diesel VW Rabbits, car pooled, etc.  But that level of change took some time.  

Our current situation could resolve itself before consumers have a chance to respond beyond minor adjustments.  If we're lucky and the damage from Katrina isn't as bad as feared, then we have to be careful not to misjudge the adaptability of consumers.

This lag in consumer response is partially due to economic reasons--most people don't have the resources to instantly trade in a car for something more fuel efficient, etc.  But it's also due to psychological factors, as people need to be convinced that the higher prices will last long enough to justify making significant changes.