While I agree that it would be best to not have to give your private key to Google, I think it would be a good start to get all email transmitted using the PGP protocol. Once the emails are being sent like that, those who don't want to trust Google, could more easily do it on the client side since it would be much more in use.
You would probably have to not use Google, since if they are unable to read your email, that kind of destroys their business model.
You would probably have to not use Google, since if they are unable to read your email, that kind of destroys their business model.