Quite unsurprisingly the US was downgraded from AAA to AA+ by S&P, generally considered as a more "lenient" rater than Fitch and Moody's. I've been saying at work that the US is remarkably similar to the UK in the fifties, and that I am awaiting an American Skylon. It was originally a structure built for the 1951 London Festival of Britain, and the popular joke was that, as UK economy at the…