I see peak oil differently. Peak oil/energy really is meaningless as an absolute. The only thing that really can matter is peak supply relative to demand, because this is what forces prices up and market changes. Oil hit this peak decades ago and is continuing to crunch slowly. Coal is likely to hit this peak soon, primarily because the cost of extraction is going up compared to yields. This means relative shrinking in supply regardless of what is in the ground.
What this means to me is that energy prices, which have been supply constrained since the mid-1970's are going to continue to go up by fits and starts, and occasionally go down but it's a ratchet overall. This does have huge ramifications all across the economy. It won't be a drastic end like many of the peakers predict but a very slow crunch.
In other words, the current economic troubles will continue by fits and starts more or less since they have since oil stopped being a demand-constrained commodity. I think you can trace most of the economic problems in recent decades to instability and supply constraints regarding energy. This has also helped fraud along, as in the case of Enron.
The more we can do without oil, the more we can do. But energy return on investment is an important problem to solve and it isn't clear we have sufficient solutions available.