Although I lost a lot of good ranking on major keywords, I think this is a very good update. Before, in my industry the top serp are sites that has huge quantity of links - now seems like yahoo also consider the quality. Like many has said the result are very similar to google. The question is how to find out the new yahoo factors. Right now the old serp for my industry still showing on yahoo non-US datacenter (it.yahoo.com, ca.yahoo.com, etc) - until they update these dc's my revenue come from non-US buyer.