The FT interviews Barclays Capital's head of commodity research, Paul Horsnell - this caught my eye:

Paul Horsnell: ... Last year there were many who put higher oil prices down to too much liquidity in the world system which was leading to too much risk-taking and too much speculative involvement in oil.
It is impossible to maintain that view this year...

Seems the speculators can't win. (Isn't it interesting how all the bullish speculators seem to restrict themselves to driving oil up and all the bearish ones are devoted to driving equities down?)