So Standard and Poors cut the US credit rating to AA+. It's not really going to do anything at all. People still gonna invest money.
Couple of reasons -
The credit rating denotes how willing a country is to pay back their debts and how likely they are to default. AAA means they make every effort to pay and there is zero chance of default. AA+ means a hair less likely to pay back their debts and a 0.something % chance of default.
Also, Standard and Poors are a fucking joke.