BlogCatalog recently launched a new blog / social search engine; view it at: (http://www.blogcatalog.com/search).

The search pulls results from BlogCatalog's directory, blog postings, discussions, blog tags, post tags, and social search. The search results are well organized, and retrieve relevant postings. I'm not sure about the breadth of this search engine, and will have to do additional testing to review this resource.