Obviously, as bitcoin gains a lot more traction it makes sense that the US wants to tax it. The more people that start using it over fiat currency means the fewer people paying taxes. So, since the debt is so high, the US would try to put into place anything that allows them to tax this new currency. Not sure what this means in terms of bitcoin price -- I don't know if it'll drop when this news comes out or not, but there's a strong chance that it will (however, probably nowhere near as much as the drop after the China news).