No! they didn't have one before. If you notice, all those news you've been receiving (along with the ones regarding search as well) have been either posted the Official Google Blog or the Webmaster Central Blog or other help centers or forums. However, this new Search blog is dedicated to search. You can get updates on search algorithms and features along with other news and stories.
In the past we’ve published information about search on the Official Google Blog (more than 400 posts about search and more than 50 weekly wrap-ups, and webmaster-oriented posts on the Webmaster Central Blog (more than 300 posts). We also operate a help center for search and another for webmasters. That’s not to mention the search help forums which have more than 50,000 discussions, and the webmaster central help forums with more than 90,000. Combine this with YouTube channels and search conferences, and it’s safe to say we talk a lot about search.
And that, “Even with all these channels, we still felt we were missing something.” This special blog for search will feature each and every change, announcement or story about search, big or small. It will also bring Google search news seekers to easily access the information they want on a separate channel. This makes sense as apparently search algorithm and features seem to be updated continually (roughly 500 improvements a year) which demands an equal keeping-up to do.