My site that survived for almost ten years was hit by the Oct 13th Panda update. I redesigned the site and saw a slight uptick over the past month, gained back about 20% of lost traffic. However, I just checked traffic since the 19th and the site took another hit so it is back to the Oct 13th levels. Very depressing!
Note that I have also been working on three other sites, all wordpress blogs. All three of them were hit by 10-30% on the 19th, although 2 of them average less than 100 visitors a day so it is hard to tell the full impact given the low weekend traffic.
Overall, it seems like the more content I write and the more I try to optimize design and the more links I work toward getting and the more social interaction I post, the more Google doesn't care. The sites that are killing my categories are all linked to from each other and owned by a company that has bought several high PR financial sites and then linked them together to form a monster network of PR 7 sites. I just can't compete anymore.
It's been a long run for me in this business - over ten years now, but I am about to give up.