Google announced that California Bay Area is also available on 3D. Users have to enable 3D buildings layer in Google Earth to view in 3D. The Googleplex is also available in 3D. Many other cities like Paris, Yokohama, Sevilla, Stuttgart, Rotterdam etc are already available on google earth.
Google also said that San Francisco is one of the first few cities to showcase 3D trees.
If any interested user wanted to build their town/city in 3D, they can do it now using Google Building Maker.
3D World channel on youtube : http://www.youtube.com/yourworldin3d