What does the US downgrade mean for you?

The asset class generally seen as the least risky in the world – US Treasuries - just got a bit riskier. On Friday night our time, credit rating agency S&P did what its peers Moody's and Fitch didn't dare to do. It downgraded the US. Not by much, of course. The country's credit rating was shifted down a notch, from the perfect AAA, to the very slightly less perfect AA+. But it does mean that US government debt – generally viewed by the market to be the ultimate in risk-free assets – now has an official question mark hanging over it. So what does this mean for you?