Google Maps implemented its own "universal search" by mixing personalized maps and KML files with standard local results. Depending on the query, you could see a group of up to three community results individualized on the map using blue pushpins. Until now, these user-created maps were displayed if there weren't relevant business listings for your query, but now they're a part of the standard results.
"The blue markers ('community maps') indicate relevant user-contributed results for your search. You can click on the 'see more community maps' link either in the community box or at the bottom of the page to see more user-contributed results," explains Google.
Google includes in the search index all the public personalized maps, but also geolocated content from the web: GeoRSS feeds and KML files. So you'll be able to find Flickr photos that have a public location or news from topix.com. The index is far from being comprehensive, so it would be nice to see in Google Maps all the content from the web related to a location: photos, videos, news, blog posts, events.