A good summary of the positions by Mark Thoma (a bit of theory)

Arnold Kling is not sure where to place his bets, but has a good counterfactual question to Krugman: does he believe oil prices were at the right fundamental level last year when they were at $60/bll. And if not, why weren't stocks disappearing then?

I think yesterday's commentary is quite convincing that looking at published inventories as data for anything is not going to be much use in determining the cause of high oil prices today.

I talked to Bruce yesterday, an energy/environment sector banker. He confirmed that processes like coal liquifaction have a long run marginal cost around $75/bll before any environmental taxes. Uncertainty in environment policy is almost certainly keeping investment down. 

I missed Brad deLong's post in my roundup the other day, and  liked this comment from a reader:

"Its interesting to me that the people who trade this stuff, e.g. Soros, are quite convinced that its a speculative bubble while those who don't are convinced that its not. We have seen two such bubbles in the past decade.  "