Who cares if we lose the standing. WE STILL WILL BE THE LARGEST ECONOMY. Its not like the economy will just die, because someone rated us at AA+ instead of AAA. We still have hundreds of multibillion dollar companies, and thousands of multimillion dollar companies, none of which are going to die any time soon.
Of course it's not going to impact on people in two days...the impact it will have is for the ability of the US to get cheap(ish) credit on the world markets to be diminished so America will be paying more to service its debts and to borrow money too, somebody has to pay for that and while one person may not notice any chance in their lives somebody will be paying for it somewhere (probably through public service cuts since tax rises wouldn't be popular).
Also, don't forget that big companies aren't going to just swallow that hit in interest rate rises, they're going to increase the rates of interest which their customers have to pay in order to mitigate against that rise hitting their bottom line profits. So you'll probably see the interest rate on things like mortgages or credit cards going up a bit too in order to pay for that.
The problem I personally have with these companies which do credit ratings is that they're completely unelected bodies who are accountable to nobody but their shareholders yet they can make these decisions which can have a huge impact on whole countries. In the example we're talking about, they've already admitted that they made a miscalculation of over $2 trillion when they were deciding on these credit levels for the US, that's $2,000,000,000,000. Their decisions have huge impacts but they're able to make these massive mistakes and nobody can hold them to account for it. That's not a good situation.