We're not doing anything different in terms of what we request from Google on our end.
Google's policy, as far as I know, is to be more upfront about what they're sharing regardless of what's asked for... and it looks like asking for email brings the basic profile info along for the ride.
Far as using this information goes, we currently populate the "real name" field (that isn't shown to anyone except you and the site's moderators) on new profiles with the name from the Google profile. We are also working on a feature to optionally allow folks to use the same avatar they have on Google on their SE profile at the time of signup. If they choose to switch to a different avatar at that time, we will not keep any information about their Google avatar.
If you want to avoid sharing this information, your best bet is to log in with a different service, such as Stack Exchange OpenID. I suggest creating a new profile using that and then contacting us to have your profiles merged. Once that's done, you can remove the Google credentials by going to "my logins" on your profile and keep logging in with the new SE OpenID from then on.