So my guess is that on Sunday they will hammer out the details, but then leave the market hanging on Monday. They will all go home and get wasted for new years, then come in drunk on New Years day and make it all good to go. We get word of that Jan 1 at around 11PM, then the futures turn green, Tuesday opens up like 300 points up on the DOW and S&P above 1430.
Then within a few days, crash and burn.