Why?
TerraGo Technologies?
http://www.in-q-tel.com/news/releases/10_23_06.html
and
http://www10.giscafe.com/nbc/articles/view_weekly.php?articleid=315831

1) Adds more usability Google maps, Google Earth and other GIS based maps.

2) Revenue stream, especially for their fee-based version of Google Maps?

3) Why this company?
It just received venture cap funding from the venture cap arm of the CIA, In-Q-Tel.
http://in-q-tel.com/index.htm

2 other services that received funding from In-Q-Tel have been acquired by Google.

A) Keyhole (aka Google Earth)
See:
http://in-q-tel.com/news/releases/06_25_03.html
http://www.google.com/press/pressrel/keyhole.html

B) Google Acquires @Last Software (Sketch-Up)
http://in-q-tel.com/news/releases/03_14_06.html