I'm still playing with it, but google blogsearch just launched. Its pretty fast and seems to be indexing pretty well. The Atom and RSS output is pretty useful and outputs the basic amount of metadata, no A9 open search extension used. Google have applied a simple CSS transformation to the Atom feed but not to the RSS feed. Theres no advertising yet, but there is a related blogs feature which isnt included in the RSS or Atom.
Is this the end of Technorati, Feedster, Blogdigger and other feed based aggregators? I dont personally think it is but we may see a shake up or at least much more creative risk taking in the very near future. But then again, theres nothing stopping google mixing up blogsearch with maps to create blogdigger's local feature. Ranking blogs to create there own Technorati Top 100 or Feedster 500. Hey may google will tie up there video service with blogs for some interesting views on the content.
But lets not forget, Yahoo still has its hand to play in this field and I think theres will be the most disruptive.