From the Associated Press on Thursday:
Standard & Poor's Ratings Services on Thursday downgraded $3.68 billion in investments backed by home loans as mortgage credit quality disintegrates, the ratings agency said Thursday. S&P cut its rating on 89 tranches of collateralized-debt obligations from 22 deals.
I can't seem to find evidence of the cuts on S&P's Web site right now, but will update this post with particulars when I do.