United States loses prized AAA credit rating from S&P | Reuters
Although the government made a debt deal before deadline, S&P still downgraded the US ratings. I think that this is more a political result than an actual rating based on the capability of the US to perform and maintain a high rating.
The S&P calculation of $4 trillion in savings required to maintain good finances is likely an exaggerated value. Although decreasing the debt by $4 trillion will be great for the economy, in this recovery time, it is not possible.
Downgrading the US will only make recovery more difficult, and will probably result in a further loss of jobs.