Let me start by stating that I have no love of the ratings agencies. People respond to incentives, and the ratings gang was incentivized during the last decade to stamp AAA on securities backed by crap and take their big fees. They were not doing the job they were set up to do, and they are scumbags!!!
But, S&P was right to downgrade US debt. In fact, just like the did with CDO's, they probably have given us a AAA rating for too long. Let's look at the facts: We now have a national debt of around 100% of GDP, like Italy and a lot of other countries who debtors are worried about. On top of that, we have a completely disfunctional federal government, particularly a Congress that is being held hostage by the Tea Party, a bunch of morons who get up in the morning in their house whose mortgage was affordable because of government-insured loans, drives to work on government-provided roads, then get on the government-created internet and use their government-taught ability to read and write to complain about how government can't do anything right.
The likelihood of our current group of politicians coming up with a solution to our debt problems that is sensible, and will allow us to continue to invest in the education and infrastructure that is necessary to be a successful wealthy country, is close to nil. The Tea Party doesn't understand the importance of government investment in human capital. And they now appear to be driving the bus. Which means we are completely fucked. S&P should have downgraded US debt after a bunch of these whackjobs got elected. If they were really doing their jobs, they would have downgraded us when Bush got re-elected, the most obvious sign that a large portion of this country is too stupid to make sound decisions.
So, get used to the downgrades. I find it hard to see much positive about the future of a country who would elect the group of self-serving, power hungry scum (and I am not just talking about the Teabaggers now!) we have in DC, and all other governments around the country.
We are at a point where we don't have any obviously good decisions to make. Cutting government spending will send us back into recession, and continue to run deficits as we do now threatens our future financial help. We have old people who depend on the government to stay alive, and we are getting older. We have tough decisions to make that require thought and cooperation.
Good luck with that!