Yahoo Search announced an update will be taking place today. They wrote the typical line:
We're in the process of rolling out some changes to our crawling, indexing and ranking algorithms. While we expect the update will be completed soon, as you know, throughout this process you may see some ranking changes and page shuffling in the index.
Update: With this weather update, you might also experience spikes or drops in crawl traffic for the next week or two.
But no one has seen any changes, no where - not at WebmasterWorld, not at any of the forums - like we typically do. In fact a WebmasterWorld thread said Yahoo announced an update, but everyone is asking if anyone else is noticing any changes. When people start noticing any changes, I will post a summary of those changes.
For now, the only interesting thing I see is a comment at the Yahoo Search Blog that says he is seeing lowercase titles in Yahoo search. I wrote about this a while back at Search Engine Land, Are Lower Case Titles In Yahoo Coming From Anchor Text, but it was fixed soon after. I currently don't see any examples of new lowercase titles in Yahoo Search.
Forum discussion at WebmasterWorld.