Now for create, edit, delete contacts you need to use the Google Contacts Api.
Google suggests:
For read-only access to users' contacts, use the People API, which provides both contact and profile information, and does not use the older GData protocol.
They say also that eventually People Api will replace Contacts Api.
Do you think that in future the Google People Api allow to create, edit, delete contacts?
Update
As Amos Yuen said, Google updated the People Api thus you can use it also for create, edit, delete contancts.
