The ratings agencies are absolutely irrelevant, especially S&P who was a prime enabler of the financial crisis. They're just saying what the market has already known and priced in. The ratings agencies are always late to the party...they make these ratings changes and the media reports it like it's a huge deal and a shock, when in reality any market participant who pays even a modicum of attention has already realized that Europe is not as creditworthy as they were in the past.
Yawn.