Well we are probably soon going to find out just quite how much oil has to do with our economy. I expect its probably been the most important driver of growth, a multiplier of massive proportions, and when it dwindles/massively increases in price we will see decline of such proportions that we we will consider it great just to get a slower decline rate, let alone growth. Having said that its possible we will still get growth in certain areas, and that we may change the stuff we are measuring so that we still have some numbers going in the right direction.
Hard to imagine this stuff not involving some ugly decrease in the quality of life, but again I think that in order to remain hopeful and thankful for something, rather than hopelessly doomed in the style of 1970s fatalism and woe, we will start to look at it differently. Down is the new up, less is more, slower pace of life & much less consumption will be a headfuck to get used to but has an upside that those lucky enough to survive the transition may yet get to appreciate.