It's awfully hard to rally with oil down, so we have to accept that this one could be a day that doesn't turn and is totally hostage to the Saudis and their desire to break the U.S. oil industry and starve the Iranian oil industry, so it can't get financing.
The fact that anyone thought that OPEC even exists anymore is convenient fiction to create news stories.
What matters is that the Saudis know that above $50 the U.S. comes alive again because of lowered costs. So, it is vital that the price not go above that so they can take market share and bankrupt the most levered U.S. oil companies,
More importantly, at $50 the oil companies indebted to U.S. banks have to sell futures to raise cash to pay down debt.
All of these will put a damper on oil and a damper on oil means a damper on the S&P 500 futures.
Just a fact of life.
If oil turns up, the market will turn up. Otherwise look for the market to head lower, especially given the employment number that comes out tomorrow.
All that said, I do like how the semis are acting. Check out Cypress (CY) (thanks Matt Horween for pointing that out) and how barely down Analog Devices (ADI) is despite the Goldman Sachs Sell rating.