I'm still very curious to find out what will happen on Monday when markets open. I believe it's going to be pretty random, markets could totally ignore the S&P downgrade and rebound, or they could fall on concerns about the US and/or Europe. It's very difficult to guess at this juncture, so I'm turning to the markets that are open on Sundays: middle east countries.
It's a mixed back — between a drop of 7% in Israel to a slight uptick in Saudi Arabia, confirming that we might also have a mixed back tomorrow in Asia, Europe and the USA. See for yourself: