Good news! :) Bill Kilday, a founder at Keyhole, wrote a book about Keyhole, Where 2, and Google Earth and Maps: "Never Lost Again: The Google Mapping Revolution That Sparked New Industries and Augmented Our Reality". It's not very technical, but it has a lot of interesting history about the products' development and internal Google politics.
It looks like a talent acquisition: the Where 2 codebase was a C++ app, nothing to do with the Ajax implementation they rolled out.
I'd be interested in learning more about this story.