Works, but... Rated 3 out of 5 stars

Brings in my google contacts, but it overrides the status bar at the bottom of Thunder Bird, so URL previews by hovering over them in email do not work. This is a huge security risk because it allows spam/malicious messages to hide their true URL.

This review is for a previous version of the add-on (1.5.2). 

it does not do this in the 1.5.3 and thunderbird 10 - seemed like a problem with some thunderbird versions