In an effort to get more cities modeled in 3D, Google has created a new category in the 3D Warehouse titled “Help Model a City“. They’re encouraging users such as yourself to go in there and help create some of these models. So far they have five cities listed — Ann Arbor, Michigan : Amherst, Massachusetts : Astana, Kazahstan : Brookline, Massachusetts : San Jose, California.
It seems like a good way to encourage more people to help model the buildings. I still expect Google to create a semi-automated process to handle this (similar to how Virtual Earth does it), but in the meantime this could help get more buildings up there.
The Google Lat Long blog has more information.