Blog search engine Technorati has long billed itself as "telling you what's new" instead of ranking old documents based on a relevancy criteria. That difference can be important when you're looking for breaking news or interested in the latest thing that's being said about Katrina, for example. I think it's that difference that explains why Google launched a blog search engine today.
I've wondered since Google bought Blogger when they were going to combine search and blogs in a meaningful way. I'm sure that blog search engines have mixed feelings about the launch. On one hand Google's entry legitimizes the space. On the other hand, competition just went up an order of magnitude.
Google's new search tool is fast, just like you'd expect. The index still leaves something to be desired and there's no form to tell Google about your blog. The FAQ says that if your blogging software pings weblogs.com (which most do) Google will see it.
Dave Winer says that Google's reading the RSS feeds but isn't indexing posts without titles. Interesting. Most people probably put titles on posts by default, but some (like Dave) don't as a matter of course. That's why it's beta, I guess.
One cool feature: you can subscribe to the Atom or RSS feed for a search, seeing the results, as they change, in your favorite feedreader. I wish they'd add that to the main search engine!
A number of the Slashdot crowd are hoping this signals a change in the page rank algorithm to give blogs less relevance. That's ironic since I consider Slashdot one of the premier blogs. I don't know whether Google will make that move or not, but I hope not. That's not just a selfish wish, but a recognition that I often get the best answers to queries I type into Google from Web sites that happen to be blogs.
Like other search tools, Google's blog search interface is spartan. That leaves plenty of room for others in the blog search space to innovate. Technorati, for example, has been working hard to get tagging integrated in a major way and to integrate with the tags from del.icio.us and Flickr. That kind of value add is what will keep them alive.