asusplay - 11:03 pm on Oct 5, 2011 (gmt 0)

Did something happen yesterday (Oct 4th)? I lost about 70% of my organic traffic on the 26th, and suddenly yesterday I lost a further chunk of traffic so now I have lost 95% of all traffic. I am seeing the same today which is why I wonder wther there has been a mini update? Also the number of pages indexed on GWT is only half that of the URLs submitted in the sitemap, which I don't understand. Anyone else seen this?