Google +1 button/Google+ Badge update: JavaScript Loading

What Google says about this change in there email

Today we’re improving the performance of the +1 button and the Google+ Badge. This change will first roll out to this preview group and doesn’t require any change to your site. It reduces the size of the / js/plusone.js loader, while making it smarter: it now will load only the code necessary for widgets it finds on your site. In addition, the
full +1 button code has been reduced in size by roughly 20%.

We’re turning on this change for the preview group to give you an opportunity to test the changes on your web site and ensure the +1 button and Google+ badges function properly. This change applies to all supported browsers in all environments.

This is an invisible change aimed at performance and stability