I suppose what I was getting at with the partisan thing was to stop it turning into a slanging match.
I've gotta agree with that point on showing off to their bases, it seems both parties are trying to take an ideological approach to the negotiations, with the Republicans saying "no new taxes" while the Democrats say "we aren't cutting welfare". Problem with that scenario is that the other side can use that to say, "well, we are trying to make our way through the issue, but the other party doesn't want to play ball". Like you said, its a massive game of chicken right now, hopefully it can be resolved fairly quickly.
If it doesn't get resolved, the implications are pretty huge. I mean, in asset pricing US treasuries are basically considered the "risk free" rate that all other asset prices are based upon; if the price of US bonds was to rise it would push all asset prices up, leading to deleveraging and the potential for a second global credit crunch, which is certainly amongst the worst things that could happen to the fragile global economy at the moment - just behind asteroid or supervolcano.