So, after a year of blood, sweat and tears repeatedly appearing at exactly the wrong time to get my patches in, I've finally managed to commit my patches to Evolution and evolution-data-server to port it to use libgdata rather than its home-grown libgdata-google library. Since Evolution has switched to using CalDAV for its Google Calendar backend, libgdata is just used for the Google Contacts backend. This is the first outing into the big scary world of popular usage for libgdata's Google Contacts support, so any and all testing of the changes would be appreciated.
In the meantime, I'll get back to looking at adding support for any additional features/contact fields I can to the Google Contacts backend.
Nice, good job has been done with libgdata!
If you need some help for anything I could spend some time on it. I hang around #libgdata but t's not actually so full over there.