In other words it represents the best case scenario if there's no political upheaval or pervasive economic shocks so that the industry can go about its business without interruption. Unfortunately, I'd say that would be incredibly unlikely. The global economy has been grossly destabilized in recent year by the giant conveyor belt carrying wealth to the US, which is likely to break down in the not too distant future and wreak financial havoc. In addition, even a perception of shortage in a commodity as strategically vital as oil could (I think would) provoke resource wars and gunboat diplomacy. The impact of that sort of human behaviour on energy supplies would be nothing short of disasterous, but, in the absence of the global trust required for a Powerdown scenario, it seems to be what humans typically do in response to resource shortages. Sadly, I fully expect the human aspects of peak oil to magnify the effects of peak oil very significantly. There's no room for complacency.
When Katrina and Rita caused shortages, the response was cooperation, not conflict. In fact, there are many examples of oil cooperation: Russia helps out Belarus. Venezuela and Mexico help out Cuba and other Carribean nations under the San Jose Pact.
Your faith in human nature is touching JD. I don't share your optimism. We are talking about a much more profound and widespread crisis than a single hurricane in a localized area surrounded by a functioning economy.

There were elements of both cooperation and conflict in the response to hurricane Katrina. See here for instance: http://www.fromthewilderness.com/free/ww3/092105_world_stories.shtml#0.

I would say we are in a state of mixed messages at the moment. People are worried, but so far the economy has held up despite the increasing stresses upon it. Once the positive feedback spiral visibly changes direction (as opposed to hovering near the cusp as it appears to be now), the human response is likely to change dramatically for the worse. The psychology of a bear market is corrosive. It undermines the ability for populations to respond rationally, thereby compounding the effects of the initial problem substantially.

Do you really think the US would refrain from making further pre-emptive resource grabs, trusting the Chinese and the Russians and everyone else to refrain from doing so as well? I'm sorry, but I see a tragedy of the commons situation here. I think the US will be busy blaming China, and anyone else it can think of, for the collapse of the American economy as the credit bubble implodes. Trust will be in very short supply and without that, cooperation is impossible.

I should point out that trust is still possible locally under such circumstances, it's just that the trust horizon contracts. In the 'us' versus 'them' equation, 'us' becomes ever more tightly defined and 'them' becomes an ever more pejorative term. In times of plenty (or upswings of optimism), 'us' may be almost global, in a 1960s brotherhood of humanity sense. In resource constrained (or pessimistic) times, 'us' may shrink to the point where it includes only those in the same area with the same values and in the same boat. At that level, the value of cooperation and the price of conflict would still be clear.