The Oil Drum

I predict many, many will chose this alternative. Many will take a left turn off that bridge.

It's a pity that they'll also be filled with toxins and pharmaceuticals from modern life when they decide to give up... they would have made great sources of protein for those who choose to try to survive.

Seriously though, it is impossible to know how much a complex system as our modern world will react to the decrease in energy inputs that runs the show. If we want to look at movies for some possibilities, all three Mad Max movies showed different shades of a post-collapse civilization. There were shops and tourists in Road Warrior, pretty much all chaos in Thunderdome. Both were set in a time that appeared to be past some sort of collapse point.

If we don't end up with some technology miracle, my guess is things will slowly get more and more uncomfortable for a while, eventually reaching a snapping point when all hell breaks loose, and after a relatively short period (perhaps a decade), the survivors will be fatigued and try to settle into the new realities of life, building a civilization that isn't as easy as our current one [is for industrial nations] but much better than Thunderdome.

This is provided that no one decides to release the demons of NBC weapons which really could screw things up for centuries without doing much good for those who used them. If we can avoid that, it may be that current third world type cultures, especially the most primative ones, end up fareing the best.