Minimal. You could take a very aggressive view on the default risk and not "bet the farm". FX futures options, gold, etc. I don't agree with half the fire and brimstone on that site usually, but Tyler Durden et al are very sophisticated traders. Theres no way they just maxed out in a 3x bear ETF and held their breath. By the way I don't think equities rally more than 2-3% on this, but implied vol is going to get killed. Funds were getting flat on risk, not short going into the weekend. There shouldn't be a squeeze coming out.
I'd say the overall short interest in the s&p would be much less over time without that website. Having said such, markets would probably not be up here without them.
This is essentially Boehner's plan, so Moody's should reaffirm AAA rating, per its friday statement. With negative outlook though.