First we have to look at the Dollar, although most of the downfall off oil is due to a lack of demand the strength in the dollar recently has helped push oil down.
USD= Broke out of its ascending triangle and should make 3.50 point move to 89.50 which would put it at a key resistance level.

USO- broke below its descending triangle. Plus its below its support of around 28. This move should move USO back to 24, which is also a support level.

Plus watch the EUR/USD if it breaks 1.29 it will give support to the dollar rallying. Right now we have some support at 1.2926 level.
To the SPX:
Bears= Watch 840-850, if this level gets taken out with strength the bulls will have some strength in them. Watch the MEGA Charts for breadth and volume
Bulls= Need to hold the 20EMA and the 820 level, which looks like we might open right at that level and must also hold

Watch the volume and breadth if we have a strong move down again $NYMO could break zero, sending a short-term sell signal.