There have been some rumors Yahoo announces a blog search of its own, countering Google's recently released blog search. The announcement is supposed to be made today or tomorrow. Could be FUD. Could be real. Maybe the following URLs are worth watching?

blogsearch.yahoo.com
search.yahoo.com/blogsearch

This one could have been it, but the first one points to Yahoo 360 already:

blogs.yahoo.com
search.yahoo.com/blogs