On Tuesday Google added a Wikipedia layer to Google Maps, yesterday real estate was added
Google Maps API for Flash
The other big announcement made from Google is the Google Maps API for Flash. This new API means that Flash developers can start developing Google Maps mash-ups.
An early example of Google Maps in Flash is this Map Photo Gallery (hint: click on the 'show photo gallery' button at the bottom of the map).
Another early example of Google Maps in Flash is an application from Navx. This map contains a huge database of different collections of locations. Users can add their own collections to the map so this database should grow and grow.
The Google Maps API blog also has another example of a Flash map that is synchronised to a video. When the location in the video changes the map automatically centres itself on the new location.
Just looking at these early example it seems like the Google Maps API for Flash will open up whole new areas for Google Maps mash-ups.