You hit the nail on the head. This is really the effect of the massive credit bubble - natural resource companies and financials. Given the way things are going, we will likely see a lot more of this in the next decade.
I'm not sure how natural resources are a bubble. They might not compete in the same way companies which innovate on their products do, but they're certainly not under-valued. Financials, on the other hand, are a bubble in which major shareholders have complete control of the legislative process in the US. Consider the power of the federal government to bail out those "too big to fail", and that bubble seems pretty unlikely to pop.