A lot of people have been seeing new Google Base verticals popping up - and indeed the Google Base homepage has suddenly had a number of new categories added to it. As I noted on ZDNet, the full list is now:
Screenshot of Google Events
While the 'blogs' category seems odd and the 'protein database' too niche for most, some of these new categories are looking very usable for mainstream people. If I was one of the little Web 2.0 events startups, I'd be pretty worried about this. Google Base is basically Google's database of structured content and once they start heavily promoting Google Base to the masses, via the Google search homepage, it'll very easily dwarf the databases of all the little vertical players.